I know, I know this is some SERIOUS neglect and I should be shot... (Just not by RED675) Any suggestions how I could unscrew/remove this bolt without bending or damaging the Rad arm for the Fan... As replacing the Fan.
Stud extractor, may well be able to bite down on the bolt head from the outside. I got mine off eBay, bloody good bit of kit.
Use an angle grinder with a flap disc the head of the bolt down and do it abit at a time Or hacksaw blade inbetween the gap
If you f@&)£ it up you can secure it with the other two bolts and run a cable tie through the rad on the third so don’t panic too much