Well even if you found the old one it would not be valid because it is dated to start and end at a specific time.  And by your own admissions it is ending.  So yes, just get a new lease and prepare it with the same information as the old lease, unless you are re-negotiating the terms such as an increase in the rent, then put in the newly negotiated terms.  Date it the start date that you wish it to begin and the ending date. You should put something in if you are carrying over the prior security deposit from the former lease.  Then just give it to the tenant to execute and then you should execute it as well.  And make extra copies this time.