How to perform mass migration from one player to another?

Hi. Let's assume we have two player servers: wpm1 and wpm2
20 transactions are assigned to wpm1 and 30 to wpm2

And someday we need to update Windows Server on wpm1 node.
This operation could take a while, so we need to migrate this 20 transactions from wpm1 to wpm2 to avoid data loss and keep monitoring service availability.

How to do it?