Where the full amount of security deposits paid by tenants will not be transferred at settlement, seller will furnish to buyer in writing the tenant's names, the amount of the security deposits, the amounts deducted, the dates and reasons for deduction and the tenant's written notification or acknowledgement of the deduction."

I know all states are different, but share a common rule that landlords must acknowledge and respond to problems within a certain time frame.

I remember submitting paperwork that would take months for them to acknowledge.

@Ned Carey - I tried to tie you into the above response, but I guess it was too long by the time I got to that... here's acknowledging your approach to attracting help - I liked it!

Do we need to amend the lease at all or sign anything acknowledging they now have a service animal and the rules that come with?

But you're trying to tell me the way I write is problematic while not acknowledging those who came in here with a nasty tone and nasty words.

When your next tenant moves in, take 100+ photos of everything and list any damage/ stains that you didn't fix on an addendum for the new tenant to sign acknowledging the condition. 

You would probably win legally but don't think it is worth the argument.IF this is a good tenant that pays on time and has been in the property for some time, I would probably pay the cost of repair and get them to acknowledge (in writing) that the opener will be considered an appliance going forward.

Of course, if it's not recorded and/or the seller is not sharp enough to make you sign an acknowledgement of the option, then you'd have a law suit on your hands.  

Make it an acknowledgment that there are stairs, and by signing the document, he acknowledges that he will hold you harmless of any injuries resulting from the presence of the stairs.