Tenant Agreement with new owner

[Enyi Ajoku]

I recently purchased a 2 unit MFH. One of the units is occupied with a tenant who has a lease agreement with the previous owner. I'm i obliged to agree with the terms in the agreement? I have read through the agreement and its fine by me. But i don't feel comfortable holding to an agreement that was done with the previous owner and the tenant. 

I was hoping i could have a conversation with the tenant and let them know that i would like to change the signatories to the lease from the previous owner to myself and the tenant