these often refuse to come off because there develops a wear lip on the edge of the drum
however if you look at the wheel locating pegs you will notice that these screw into the hub only as the hub has a larger more course thread in it
now the clever bit
go to a scrappy to the vauxhall bit and find a 1.o litre 3 pot engine with exhaust manifold on
remove two of these studs they are the same thread pattern as the punto drum
you will notice ive fitted and migged a 19mm bolt on the ends of mine so i can get more leverage but i used them as they were originally with mole grips

the art is to screw them in a bit at a time and the stud hits the flange thus pulling drum over the sticking shoes
dont do it all in one wind them in and out a few times and then drum usually pops off
a bashing with a copper mallet helps too

remember this is in the locating holes NOt the wheel bolt holes