new tenant - old pm - can I change rental agreement w/ tenant

Greetings;

I am wondering if can modify a lease agreement (1 yr) with a new tenant after firing the old PM? There are things the PM didn't include in the agreement that I requested. Or am I stuck for 1 year til we either sign a new agreement or they move out? The tenant has not even moved in yet, but signed the lease - will move in Oct 1.

thanks in advance

Kelly