to tofu: all the responses are correct....even though some kits are already predrilled, it still may not fit to your liking or may not fit perfectly. most fiberglass kits require u to play w/ the kit until aligns perfectly... As for my blackwidow sides and rear, i had to play with it to make it fit correctly, and i still had to drill in some areas so the bumper wont wobble, or to make it align correctly. You'll see, what i mean when u have your own kit. You have to drill into the frame, and no, not all kits come predrilled. As for how many bolts that held my kit, i had 4 in the rear and about 8 on each sideskirt... 2 in each fenderwell (4) and about 4 across the length of the kit. Keep in mind, it really depends on what kind of kit your getting. As for me, i'll never deal with fiberglass again..too much headaches...
Nossy is right too, reason its easy for me to take off my kit, is cuz i've done it so many times. My first time took me like 2 hours to align it all correctly. Also, do u really want to take off the kit after u put it on...its fiberglass...that shit is delicate....if u tighten the screws to tight, it will crack, if u use the oem clips, it will crack, if u bang on it, it will crack....i personally say, once the kit is on, leave it on, until u crack it, or decide to sell it.
welp, thats my two cents....my advice is look into a kit that u like, and ask others what they think of it...i bought my bw kit, and after a month or so..I HATED IT, cuz i just out grew it...i sold it for like a bill..so i lost about 8 bills in prep and paint. I ended up with the oem kit...so i guess i went backwards in the evolutionary trend in fixing up rides..hahaha