You might find the property you buy is landlocked and your first job as the new owner is getting legal access.As for access to the interior of the house, if you have a battery powered drill you can get access. 

Given that it's an ADU and you are an owner occupant I would courteously terminate the lease (the how on this is going to depend on your local laws and your lease) and get a new tenant ASAP.

Problem areas are usually anywhere there are connections, such as at terminals or especially if new copper wires are connected to the old Al.

What are the current lease clauses for early termination?

If they don't do it, the lease will be terminated.

@Joseph WeisenbloomWhat’s your termination rights in the lease ?

Quote from @Matthew Ginsberg: Start termination.

As a PM, I would be worried if a new owner did not ask me at least some of the following:- Company Specifics: first question should be are they licensed (how many properties do you manage, what type/class of properties do you manage, how many property managers on the team, how many years have they been in operation)- Pricing (what is the cost to manage the property (ies), is there a leasing fee (commission structure), is there an onboarding fee, is there an early termination cost, are there ad-hoc costs for maintenance, tenant screening, or miscellaneous costs - such as to appear in court if you have an eviction)- Service offerings (do you have a maintenance team, do you come equipped with a list of contractors/vendors, do you offer the software and portal access for tenants/owners, etc.)- Financial Services (you (owner) should think about what you want the PM to handle, if it is everything from paying bills to insurance procurement to P&L statements then ask that, if you don't want the PM so heavily involved in financials and just more on the surface level of the operations of the property then that is okay too!

If you're only keeping the PM for a short time, I would only ask what the process is for terminating management and determine if you will have to pay any penalties.I would also consider keeping the PM.

If there is no agreement on price, you can terminate the deal without risking losing your earnest money respectively.