well where it's verry corroded, i would try drilling first and see how much of the weld still remains holding that to the subframe. i had just a sliver of steel that was holding mine on so i was able to just rip if off with pliers. if that dosn't work than i don't know mang. good luck.

edit: after you drill it and are able to get the lca out, just bring it to a machine shop and they can drill that welded bolt on a drill press with a larger bit or if you have a drill press, DIY