Ideas on retro fitting wheel well inserts

the plastic wheel well inserts on my Cherokee are falling apart so im installing new ones. my problem is that I cant remove the fender flares because the bolts break. they are stainless I think… the holes on the new inserts are big enough to fit over the bolt and nut, but I still need to fasten them there.

I guess I ll drill a few holes and seal around the old bolts. not much room to drill tho.

any ideas? I m going out to start now, I ll check back after I cross the rubicon. I figure that once I get halfway done I ll have no choice but figure it out…