Wire brush-USE SAFETY GOGGLES...I have seen the wires in eyes it’s not pretty. Sorry, pet peeve.
If you use that portable kit or a sander, use a shop vac on the opposite side and a blanket or tarp to keep the dust out of your interior/electronics.
I live on the coast and do a lot of duning and wheelin. This is unfortunately very common in all trucks that we play with over here. We do 4-6 trucks a year like this, and we use scalers and an old triangle wood sander backed up with a dremel with a 400 grit rotary bit to save as much metal as we can, then if we don’t have to weld them up, we prime with self etching primer, scuff and use cheap ass Napa Duplicolor bedliner under the cab and in the interior, then replace the carpet. However most of the cleanups lately l, we have been putting dynomat over the top and replacing all of the carpet with vinyl or rubber floors.
Just a bit of experience to share.
S