Question about current leases on acquired property

[Joe Miller]

Hey Everyone!
   I had a question regarding how to handle a property that currently has tenants that I am looking at acquiring. The lease which I think seems pretty extensive/quite good belongs to the management company that is currently managing the property. When I acquire the home how do I go about this. The lease has a statement that says "If this property changes Ownership due to sale, foreclosure or deed back to the lender then this lease may be terminated with a 30 day notice unless the new Owner agrees to continue the lease and both parties wish to do so". Overall, I like the terms the lease has set forth but I would need to change where the rent is going to go. 

Would I need to draft a new lease and have the tenants sign it based on these changes? Can I use the current lease only changing the payment information? If I have to change the lease is there any documentation that has to be done outside of the conversation/documentation between myself and the tenant? This is an Oklahoma property not sure if that is important to note!  

Appreciate the help! I am excited to take the dive into real estate with this house hack... Hopefully! Haha