Are they easy to change?
Very easy. Once you unscrew the pickup(s), the p-up cover pops right on/off.
Depends. Chrome covers are a pain to get off. The pickups are covered in wax before the cover is put on. If youre talking about EMGS...you cant take them off. Er...you CAN...but not without damaging the pickup.
If your cover fits then its easy. Getting the pickup out to where you can change the cover may depend on your skill level.
putting on a new cover? then ull probably want to repot the pickup. (dip it in wax)
Its not easy. Especially if its a humbucker. The last set of burstbuckers I had in a les paul were actually soldered on + the wax that was in them. Needless to say I never got them to come off.
I just saw the 1st guitar in his sig., the rebuilt Squier. So, I was assuming he's talking about single coils.
^ohh. yeah that is simple.