Exchange 2007 Server demotion from a coexistence environment with 2010

Hello guys,

We have a solution of two email servers based on Exchange 2007 and the new 2010. I have all mailboxes migrated (but Public Folders which is another posted question), all under the same domain.

Mail is working perfect, but would like to know how (assuming my PF issue is resolved), what are the steps not on the recipe (taking out role by role), that I have to consider to avoid any downtime with mail customers.

I really appreciate your advise!

Thanks for your help.

Warren