2 ways I know how. When you go to print an individual mech, it gives you an option to change the P/G in the print window that pops up. Other way is to add the mech to the force list (clipboard with the green plus sign), bring up the force list, and it will give you a Excel like grid with unit information. Two of the columns are piloting and gunnery, and you can change them there. From there you just print the mech or print the entire group of mechs.
Edit: When I say you can change them in the force list, I don't mean the override skills boxes, though that will work. I mean actualy double clicking in the grid will let you modify the number there.
