I have 98 stratos trail trailer. My bunk brackets have broken. I have purchased new ones my issue is the bolts are welded on with rust, to make matters worse the heads are trying to round off on removal so I stop extracting. I need suggestions on removal! Is it best to drill? Grind off heads? Heat and melt off? Both the nut and bolt try to round off! Any advice would greatly be appreciated. My bracket type are the swivel bunk brackets!