Either take the bracket off, ground the welded nut off them
and re-weld a new nut on or get drill them out, get a slightly
longer bolt, and put a good nut on the backside.

I'd ground off the stripped nut and weld a new one on in its place.

1995 Trooper LS auto 3.2 DOHC /w SOHC intake
1989 Trooper 2.6 auto
1989 I-Mark RS DOHC 1.6
1991 Stylus XS DOHC 1.8