I wouldn't drill it cos if it doesn't end up coming off you will be SOL as the pulley will be out of balance and it'll toast the bearing in the alternator.
Did you use an impact gun on it to reomve the nut, and liquid wrench?
BTW the mini propane torches are cheap from the local harware store, they run like $20 in the plumbing section. You should be able to find 'em in the UK too.