I believe Araldite is epoxy. It should soften with enough heat. But recent threads discussing leaks at filler necks on ally tanks presented images with tabs of metal around neck to secure to opening plus an adhesive. So it may be more complicated than just softening the adhesive.
I do not understand need to fully remove neck for painting. If trying to prep area under overhang of neck, a chemical stripper or sandblasting should to it fine.
Be sure to not have the neck sealing surface painted as I recently found paint lifting on the surface, likely from fuel exposure and causing poor sealing. Have now removed it using a razor and a little emery cloth work to give smooth bare metal. No more leaking.