You have to leave your opponent to think you are a weak opponent. Then he will underestimate you and you have a better chance of winning.
How to win vs Higher rated opponents ?

The best advice is to sail close to the wind.
That is, play as complicated as you possibly can without going overboard. You won't stand a chance in a quiet position. Challenge your opponent from move one, and keep the pressure on. Play your best opening, and keep a positive attitude.
Don't even think of offering a draw, and if your opponent offers one, plan to refuse it unless there's clearly no winning chances at all.

I agree that the lower rated player has a better chance in complicated, open positions.
But I don't agree about turning down a draw offer unless no winning chances. You need to look at the Imbalances on the board and decide if you have better than even chances -only then should you not offer/accept a draw. I recently offered a draw that was accepted by a higher rated player because I could force a draw by repetition. I did so because he had the Bishop Pair and I didn't in a game where the endgame would be an open position with pawns on both Q & K sides, he had a superior pawn structure, and his King was much better protected than mine. I had won five straight games against higher-rated players before that game so I didn't offer the draw lightly. I simply saw that the likely outcome without forcing the draw was a loss.

If you improve your chess, you should be able to beat higher rates players. It's really that simple.

I don't really agree with the "play complicated to win" idea. My USCF is 2158 and I am very pleased every time someone lower-rated plays sharp, tactical chess against me. Often the higher-rated player's superior tactical vision will close out the game quickly. My advice when playing higher-rated players is to play solidly. They will often get impatient and overextend, after which you have chances to gain the advantage. Works for me. Plus, you will learn much more when analyzing the game than you would if you lost by making a simple tactical blunder, and will learn much more about typical opening positions in the opening you played. That's my opinion.

My chess style is really positional and I hate playing complicated positions. I also really like trading pieces. My fide rating is 1880. When I play players rated 1650 I usually win in equal endgames or in slightly better endgames. How should I play against higher rated players?

EndgameChessMaster, your advice is good if you don't mind giving up draws. You've earned quite a few draws to players rated over 2200, but so far you've only won one USCF standard game against players who are clearly higher rated than you.
Also, the advice I gave was for class players. Most class players who describe themselves as positional players think they are positional players because they prefer quiet positions.
As an expert myself, and as a coach, I've seen countless games where the lower rated player reaches a quiet, equal position, then gets blown off the board because they don't know how to proceed. Quite often, the lower player offers a draw just when they run out of moves. They seem to think that since they can't move, neither can their opponent.
I stick by my advice.
Btw, MickinMD, your advice about playing for a draw when the only alternative is to lose makes perfect sense. I agree completely that you should take the draw rather than lose. But you should play to win until that time.
One of the great advantages to playing for a win against the better player is that you learn more! You test yourself by playing the very best moves, and if you are beaten, you will learn something.
The corrolary to my recommendation is that when playing lower rated players, play aggressively for the win, but don't be afraid of simplifications that favor you. This is advice that the Soviet players used to follow in the Olympiads of yore.
Tal relates that he was told by the national team coach that Soviet players understand quiet minor piece endgames better than anyone else in the world. Don't be afraid of simplification. Of course, Tal himself didn't start to follow that advice until he was older. In the 1970s, long after he had won and lost the World Championship, he strung together some incredible unbeaten streaks and became only the third player to break 2700.

Btw, EndgameChessPlayer, you're doing great as a junior! I expect you'll break master within the year!

Thanks for your encouraging comment, SmyslovFan.
As for the matter of "giving up draws", I am not really unhappy with that. Often the higher-rated player, when he/she sees the game is getting close to a draw, will try to complicate the game, giving you good winning chances. In fact, a few of those draws against masters were in that same group, ending in draws only because I failed to convert an ending (material up). But I was giving this advice for players around expert level, for class players the advice is nice. I don't think it would work so well in different matchups (ex. 2100 vs 2400) because the gap in understanding is so great. As a class player playing against higher-rated opponents using sharp, enterprising chess, I scored some upsets, but found it doesn't work as well near expert/master level.
And against lower-rated players, I stick by SmyslovFan's advice. It's brought me good results.
This is a really interesting concept, there are many different opinions to be considered. I expect many different opinions will be posted on this thread (none necessarily right or wrong) about everyone's method for playing higher-rated players. This is what has worked for me, and I hope it will help some other players out.

You have to leave your opponent to think you are a weak opponent. Then he will underestimate you and you have a better chance of winning.
I found the opposite to be true. If I have a 1900 rating (on another server) I find it much easier to beat 1800 players. A lot of them seem to be intimidated just because by facing a higher rating. Similarly, they usually play much stronger if I fall back to 1700.
"You must take your opponent into a deep dark forest, where 2 + 2=5 and the road leading out is only wide enough for 1" Tal
My favourite quote ever lol. To be honest I think the best way to win against higher rated opponents is to make the position messy and complex. Maybe thats just me tho, I tend to be a lot better at tactics than most of my opponents. Check out this game I just played against a higher opponent. I lost on time in the end but had a completely winning position
https://www.chess.com/live/game/2102411731
Any tricks ?