using an electric process heater is a relatively gentle and controllable method
of applying heat to delicate assemblies, often to assist removal of stubborn parts.
The sleeve shown resisted removal with a barrel wrench type gripper, a heavy 3 jaw 
puller and some smacking with a deadblow hammer.  With heat, it came apart 
relatively easily.  The proces heaters are available in many sizes.  the one shown
is about 6 x 30".  It can easily be wrapped around objects to heat the rim.  Up to
550F capacity, though they can easily exceed that and burn out rolled up like this, 
or cause a fire if left unattended.  smt