change the default DB User

I\'m not sure I\'ve understood your question correct, if you want to replace the sa account, want a new dbo or ?. But here\'s the best practises as I\'ve learned them.

You never actually delete the sa account, in fact you can\'t. But you assign a very long and very hard-to-guess password, which you then put in a safe somewhere. This way you have this account, just in case you loose all other administrative access to the server.

Then you create a new system administrator with a non-standard name, and probably with a name that fits in your existing naming conventions.

If it\'s because sa is your default database and object owner, you can change the owner with sp_changedbowner and sp_changeobjectowner.

Best practise is to always have dbo as object owner, to avoid orphan objects.

Hope this was the answer you were looking for, if not, please try to be more specific on your question.

Thanks a lot dude.