Seller put new tenants into unit while under contract, help!

[Alex Hostetler]

Preface: Our plan is to house hack and move in asap.

We are in contract on our first rental property (4-plex).  

When we first looked at the place and made the offer 1 unit was vacant, a few days after verbal contract but before signed contract the seller put a new 12 month lease into the vacant unit.  The other 3 tenants have been there 8+ years and take great care of the property.  One of which is month to month and has been since 2013.  All of them have essentially perfect payment history going back the last 2 years, with very minimal maintenance requests.  So it becomes fairly apparent I wouldn't mind inheriting such low hassle tenants.

Is there any way to get out of the new lease, so we can move into that unit?  This is in Texas.

Thanks for the advice!