It's pretty simple. I've done it about 10 times. You just have to be careful with all the springs and wires, and when you put the board into the new frame, you have to fiddle with it to make sure the trigger will work.
It's just a matter of trial and error. If you've worked on cockers, swapping out the grip on an angel will be easy as pie for you.
Don't forget to take a look at your manual prior to unplugging any wires.