At what point in the migration process would it be wise to remove Exchange Server 2010 from SBS2011 given that the mailboxes have already been migrated to Office 365? Can it just be removed in the normal (uninstall from add/remove progs) way or is there some particular procedure required on SBS2011 ?
I note that doing it with "add/remove" is NOT the correct way! Should I have removed it before I started preparing the SBS2011 server for migration? Currently I have got as far as step 6 (prior to setting up the target server (WSE2019) but with Exchange still active/in use and mailbox content already migrated to Office 365.
When you must uninstall Exchange Server 2010 is described in the migration guide at chapter 16 How to migrate SBS 2011 to Windows Server 2019 Standard, Datacenter or Essentials. The actual procedure is here How to properly remove Exchange Server 2010 from SBS 2011