The lock may be removed by the user by deselecting the entity or it may also be removed by the Quality Center Site Administrator. Following simple steps helps in unlocking an entity:-
1. Log in to Quality Center Site Administrator
2. Expand the required domain.
3. Expand the reruired project. It would show the list of tables for that project.
4. Every project would have a Locks table. Click on Locks table.
It will display the Select * from Locks query executed by default with list of locks on the project.
5. Type the query –
delete from locks where lk_session_id=
6. Hit Execute button. It deletes the lock allowing users to edit the entity again.