I use this method to separate parts and remove hide glue.  I bought
a low-budget pressure cooker to use as a steam source.

1.  Hold glued area over the vent in the center until the glue has
softened and separates.

2.  When separated while hot scrape the residual glue off of the part.

3.  The remainder of the glue is removed with household ammonia.

Note: When using the pressure cooker make sure it is kept half full
of water at all times.

Follow instructions with the pressure cooker as misuse will burn you
and can be dangerous.

Art Tanguay