The user reservation can be removed via P00095 Record Reservation. However, you must ensure that user.xx does not actually have the record locked, ie; in use. If the record is not in use it was likely locked due to an invalid exit from the screen or app and the user reservation was then not removed from the table.
I have a UBE that clears the table each night under the assumption that if no users are on the system no records should be locked.
As a side note - this is standard JDE functionality so if you did a bit of "looking" or searched the documentation you would have found the answer yourself - likely well before someone answered on the forum. In future it would be best on your part to do this prior to posting a "someone fix my problem right now" post.