If you can get hold of any, acetone is the best solvent for cleaning before applying epoxy. At least it was when I owned a fibreglass boat, it was supplied with repair kits. If you don't have any, overtures to the domestic management department may bear fruit, they use it as nail varnish remover.
Just don't soak plastic in it, a wipe over is fine, any slight softening of the surface improves the bond.