Dear,
Crete a maintenance order and assign the materials with "-"(Negative sign) in cpmponent tab and post the issue against Maintenance order or Reservation, so that system put back the stock in respective storage location of the plant.
This normally we do when we withdrawn material for excess qty for maintenance, but used few while performing maintenance.
Here , in your case kindly consider the FI team suggestions for price variations if you are putting very very old stock in place.In this case if there is a requirement of price change.So you can do it with MR21 if required.
Regards,
Pradhu