its pretty much common sense, u dont go heat the crap out of them u just heat it up a litle bit at a time on a very light flame and a small tip like you would use for brazing, and it still takes quite a bit until the gudgens come out. Also you cant just aim the flame anywhere you want to.
and yes 7afe ones are a press fit, you will need to take them to a engine rebuilder who has a jig to get them out.