How can you remove Mempa's biting ring? (SPOILERS)

[xopherdavis]

I put on Mempa's biting ring early in the game, which seemed useful given that TNO can't wear armor. However, I am now at the end of the game with other better rings and I want to get rid of this one. The description says "nigh impossible to remove", "nigh" meaning nearly, which means that it should be possible to remove. I tried the Remove Curse spell (cast by F.F.Grace) but this didn't work - unless I didn't use it right. How do you remove this ring?

[Maverique]

I think all you have to do is use the spell on TNO or go to a merchant who has remove curse and then "buy" it for TNO.