Did the freezer trick work? If not, try filling the bowl with alcohol and sitting the pipe at an angle where enough will travel back into the stem but not out. This should dissolve some of the tars that are cementing the stem into place.
Did the freezer trick work? If not, try filling the bowl with alcohol and sitting the pipe at an angle where enough will travel back into the stem but not out. This should dissolve some of the tars that are cementing the stem into place.