if it's the spot welds broken, there shouldn't be any need to remove fender/wing - best access is by removing the door which takes 2 minutes and needs no adjustment on refitting.

Assuming the bracket is still poking through the bodyworks, forget spotweling, and just clean back the paint and grease, and MIG weld the around the bracket, effectively welding to the fender (or wing as we call it!!)

This may not look as 'pretty' as the 2 (useless) original spotwelds, but some touch-up paint, grease, and with the rubber boot on it, it's never seen anyway and is stronger.

I would personally replace the checkstrap as well.

I've done above to my 855, a 2 friends 855's and believe it or not my Dad's 4 year old S70 needed this repair!! All of these were to drivers doors.................