Stimpson Camper 2003

[JohnHenry]

Hi all i have 2003 Stimson Conversion with folding roof anchored at front by 2 ball joints bolted to van  with threaded rod embedded in glass fibre roof.One of the threaded rods has snapped and the other looks as if it will soon follow.I have acquired ball joints and threaded rod but gaining access to ball joint bolt inside cabin is proving difficult.I have removed the Stimson overhead parcel shelf behind which is the original overhead parcel shelf and this needs to come out to gain access to the bolts -any suggestions on how to do this ?
My intention is cut out the existing rod and replace it by bonding the new one in -anyone tackled this I would appreciate any guidance tHANKS