How do you adjust the parking brake on a 1999 f150 after installing new parking brake shoes?

front brakes are disk they are not adjustable. there should never be a need! if you are having problems I would say you have a stuck caliper. Dis-assemble see if the piston will move freely (and push t back in) lube all slider (contact points) and reassemble.

If there is still spongyness after a couple pumps (remember we need a couple to push the piston back out) I would say you have some trapped air in the system and would then need to bleed the brakes. (do all 4 starting at rear passenger side)