get-DatabaseAvailabilityGroup
Get-MailboxDatabase | Format-List DatabaseCopies
Remove-MailboxDatabaseCopy -Identity db01\MSP-EXC02
Remove-DatabaseAvailabilityGroupServer -Identity dag01 -MailboxServer msp-exc02
# or
Remove-DatabaseAvailabilityGroupServer -Identity dag01 -MailboxServer msp-exc02.vag.local -ConfigurationOnly
# or
cluster dag01 node msp-exc01 /forcecleanup
Remove-DatabaseAvailabilityGroup -Identity DAG1