Disjoin WinNT 4.0 Svr from W2K Domain

I have joined a WinNT 4.0 Server into Windows 2000 Server Domain by external trust. Now I would like to remove the trusts on both sides so that the WinNT 4.0 server will become an independent domain again.
Question : Which trust should I remove first ? Should I remove the trust in Windows 2000 domain or the WinNT 4.0 Server first?

Thank you very much for your reply.