Please advise on this situation.

[Shane Rawlings]

I recently purchased a 4plex in Texas (27 Jan 15). When I went to pick up the original leases, keys, and applications I was informed that they did not have a spare key for Unit B. They also informed me that they could not give me the applications due to privacy laws and the deposit checks need to be signed by tenants before they can be deposited in my deposit account. To make matters worse the lease did not have the tenants phone number on it. So after several notices left on the door the tenant finally called me and scheduled a time to sign my lease (only change was where to pay rent) and give me a spare key.  He missed the appt. So we scheduled another, he missed that one too. After that appt, his phone is now shut off or disconnected. Also being the 4th of the month I have no rent from him. I have went by the property on several occasions and he is never there, but his stuff is (looking through the window. 

Lastly I have to do some maintenance on the AC unit for his unit, but with no way to contact other than notes on the door and no key it has become complicated. 

Questions:

Can I change the locks with a notice of where to get a key, not to deny him access but to allow me legal access? 

Can the previous landlord give me the application?

How do I get access to his deposit if he wont sign the transfer check?

Thanks,

Shane