Dropouts are easy - just heat up and pull. I do it with some locking pliers clamped to the dropout, and I do the chainstay joint first - the seatstays are flexier, so easier to pop the CS joint out.

Lugs are harder - when I've done it I've cut the tubes back to about 1" from the lug, then heated and peeled from the inside. It takes a lot of care not to damage the lug.