removing specific data from membergroupids

[Bobbo]

I've got a plugin that extends many of the VB permissions out to an external datasource.

One of the things I am trying to do is make updates to the membergroupids column of the user table based on logic in my plugin.

I'm unsure how exactly to read the contents of membergroupids for a user and strip out only a single id number without changing the rest. So for example is user A has membergroupids set to 9,10, 11 and my plugin determines that this user should no longer have access to 10, I want to update that value to be 9,11.

Does anyone have some insight on an easy method to accomplish this?

Thanks!

Bobbo