The drives are fairly simple to replace.
1- ensure all power is off to the motor and control board.
2- open the top off the drive where high and low voltage wires are connected.
3- take a pic of the wires just to be sure they go back on the correct manner.
4- Remove high voltage wire and low voltage wires that power the drive. You will also have 3 large wires coming from the motor and connecting to the drive, disconnect for now but do not remove just yet.
5- There are 4 1/4" mounting screws on the underside of the drive. These can be difficult to remove, I recommend an offset angle adapter on a impact drill to make life easy.
6- Now you will be able to lift the drive up slightly from motor, but you will need to feed motor wires thru bottom off drive. All 3 will not fit thru the hole at same time, 1 at a will do.
7 - install new drive in reverse order.
Yes, I have replaced many of these drives as a hayward warranty provider.