Try pouring very hot water over the joint and "wiggle" it lose if possible.

If your near Hollywood there are at least 4 places within spitting distance of each other that sell ROOR compatible stuff.

(Hollywood and Vine)
Jollyrancher Reviewed by Jollyrancher on . Tech help , kinda embarassing I've been a proud owner of a Roor 7.0mm 45cm icemaster for acouple of years now and I used to have the factory downstem that was issued with the appartatus but due to wear and tear I replaced it with a difusor downstem . Here comes the problem , since Roor appartatus are unique from one another I bought a 18.8mm generic difusor ( stupid of me) and it got stuck during insertion, I've hear countless methods on the forum on ways to remove stuck downstems but none seems to work and breaking my Rating: 5