This seems more of a contractual issue.....possession not be given as stated in contract.

If the possum has a rental agreement, the possum can retain possession though contract end.

Also, I was under the impression that I would not ever be possessing the property, only assigning it to someone else.

Why would you think paying the landlord for an apartment your family still has possession of is a bad idea?  

So, my question is 1) how do I take possession of the property?

If you mean you take possession of the property and the previous owner still has a mortgage on it, no, because you don't own it.If you get title and you sign a promissory note to the seller to make payments (essentially the seller becomes the banker), you can get a loan for two situations: 1> a loan with a bank to refinance out of the promissory note, which pays off the seller what you owe, and places a new lien on the property. 2> Potentially a rehab or 2nd mortgage "IF" you can find a bank willing to take a 2nd position on the property.

Given that we would buy site unseen we were going to offer $75,000 (listed for $95,000) and demand the seller clears out the tenants before we take possession.

What furniture and possessions we could for into the way in kitchen, we did and everything else we had to throw away due to mold damage.

Since taking possession 9 days ago, I’ve had nothing but problems and bad news.

Only bill her for damages that have incurred since you took possession.