Move All User maiboxes:
Get-Mailbox -Database "OLDDB01" | New-MoveRequest -TargetDatabase "NEWDB02" -BatchName “DB01toDB02”

Status of the moverequest:
Get-MoveRequestStatistics –Identity "DB01toDB02"

OAB generation to another server:

Get-OfflineAddressBook | Format-List
Move-OfflineAddressBook -Identity "\Default Offline Address List" -Server NEWSERVER

Move Public Folder Content from One Public Folder Database to Another Public Folder Database:

C:\Program Files\Microsoft\Exchange Server\v14\Scripts\MoveAllReplicas.ps1 -Server "oldservername" -NewServer "newservernamehere"

Move Arbitration mailbox

Get-MailboxDatabase
Set-AdServerSettings -ViewEntireForest $True
Get-Mailbox -Arbitration
Get-Mailbox -Arbitration |fl *database*
get-mailbox -arbitration -database "Mailbox Database OLD" | new-MoveRequest -targetdatabase "Mailbox Database NEW"

Clear all completed move requests
Get-MoveRequest -MoveStatus Completed | Remove-MoveRequest

Uninstall Exchange 2010

Verifiy there are no messages in the queue on the server
verify that there are no receive or send connectors on the server
goto start Add/Remove Programs uninstall Exchange Server 2010

open ADSIEDIT.MSC from your Domain Controllers and navigate to
Configuration -> Services -> Microsoft Exchange -> { Name of Your Organization } -> Administrative Group -> Exchange Administrative Group -> Servers -> { Your Server Name }

If uninstall was succesly your server should not be listed anymore

 

Errors during uninstall:

Error:
Setup cannot continue with the uninstall because the 'beremote' () process (ID: 4936) has open files. Close the process and restart Setup.

Solution: Stop the service Backup Exec Remote Agent for Windows

Also refer this:  http://technet.microsoft.com/en-us/library/gg588318.aspx

https://social.technet.microsoft.com/Forums/exchange/en-US/1ab0cb94-7f38-4d3c-bc1d-f27ab4f80129/removing-first-exchange-2010-mailbox-db