samba - Aug 2007 - reset AD domin membership non destructively

greetings,

How do i go about reseting my server's domain membership.

I know I need to do "net ads leave"
reset the account in the domain.
rename the secrets.tdb file

where I'm confused is what files to keep in the var/cache/samba directory.
 I know I need to keep the winbindd_idmap.tbd file.

what else do I need to keep?  what should I definitly get rid of?

I know how to do the join.

I'm just seeing some strange problems.

Thanks
Fred