A strap wrench from a home improvement store is the tool for the job. Use it on one ring first and then the locking ring after. If you put the reel clamp on first and pay attention to the alignment, it will help prevent the seat tightening from twisting the reel off center.
Check when you’re done and make sure the reel is lined up with the rod guides.
If it is off, then loosen in reverse order and start again.
We are normally only doing this with rods with metal reel seats. You would have to be extremely careful if you use it on composite reel seats as you can easily strip them out.
Don’t forget to Lube the Reel Seat