Depending on how your agreements were structured, it could mean an eviction or an ejectment action.

You should make it a point to be aware of redemption and ejectment times.

In most jurisdictions, a L/O can be an ejectment proceeding, more like a foreclosure than an a eviction.

IMO move on until you can acquire it in a conventional style or he agrees to help you finance it.What is your dads thoughts on this entire thing, particularly if this tenant gets ejected as soon as its sold?  

She pretty much wants to sell the house without being able to see it AND also occupied by her stepmom.In my perfect world, I'd offer to take ownership of the property and handle the ejectment but only pay the seller my offer price once the property is vacant.

So you could end up having to file for ejectment at the Common Pleas level of the courts (same level of court as is used to get foreclosed occupants out).So let's back up a bit now.

AR law disallows you "force" the tenant out using measures like changing the lock, terminating the utilities, etc. but if you serve an eviction notice and they fail to comply with the eviction there is a specific methodology and process (this part requires a lawyer) that will ultimately end in the Sheriff forcibly ejecting them from the property.  

Then you would be required to do a Common Pleas law suit called ejectment, can take 6 months and costs thousands.7. 

If you can't get them out of the house, you will have to do an ejectment lawsuit.

You show them that working with you is not going to make them money, they will eject you through the sunroof with that James Bond ejection seat.