Unfortunately, Craig's link is only applicable to SEMS and not SEE, and I am not aware of any Symantec documentation for this.
Neither have I attempted this myself, but I'm pretty sure it's possible. At a high-level, I would imagine the below would work:
- Setup additional SEE Management Server in new domain that is linked to existing DB (perhaps using SQL Auth, if trusts are not in place)
- Create/Amend routing, name resolution, service accounts to support new SEE MS for client check-ins, as necessary
- Issue "Change Web Access" command from existing SEEMS to tell clients to use new SEE MS details
- Migrate windows client from existing domain to new
Obviously, that's taking a very SEE centric view of things. If you're looking to rebuild your existing user-machines before adding them to the new domain, then you could treat it all as greenfield and go with entirely new and separated SEE estates.
It's all up to you.
I'd highly recommend you contact a Symantec Partner (such as ourselves) for your region, to ask about PS or advice in this. And of course, do it in test first :)