A real castle like those in England don't move. They are to heavy and aren't alive to move.
To castle in chess it will be necessary for you to clear the bishop and the knight from the kings side.
They when it is your turn you pick up both the king and the castle and place the rook next to the square where the king was (f1) and place the king next to the square where the rook was (g1).
Look at the example I made for white and for black.
Both are going to castle.
To Castle Queens side is a little different. Still the rook has to be placed next to where the king was.
Black castle Queens side. It is the same with white.
There is an extra space on the queens side. It's the "A" file.
I hope this helped you out.

How to do a castle move?