You will submit that to escrow, however some escrow companies will require an Addendum/Amendment to the purchase agreement that memorializes that the buyer assignment is occurring and the seller will need to sign that. 

You can amend open years to correct the basis and depreciation. 

Or if negotiating a renewal, add a few points to the 'Amendment to the Rental Agreement' (after the new dates and new rent is called out):-Maintenance requests or repairs will be scheduled for repair within X days of their request.

If I operate a rental property within a state to a resident of that state, it should be outside regulation of the Federal government.Taking clause of the Fifth amendment states "Nor shall private property be taken for public use, without just compensation".

Or we don't need to do any cleaning, just have them swap personal items, and sign a lease amendment to say the new tenant will be responsible for the rent and damage.

The seller and Realtor discuss the pros and cons of things such as this, as well as whether the seller wants a see any further offers after going under contract.These points can be amended if the seller changes their mind.

I have sent in an amended return 9 months ago but they still have not been processed.

Your text will likely override your written lease since you agreed to amend the lease in writing (text has been held up as "in writing").

The reason I am thinking about this as opposed to making an addendum/amendment is that I may have misplaced the original leases (organization is a skillset that I need to work on); also I am thinking of doing a refi/cash out for future deals which would need these leases. 

@Kim Meredith Hampton Do you have any suggestions or advice on how to amend the situation with the tenant?