This process and your effort should start with a purchase agreement. Get that and then go to a title company/attorney and be prepared to spend about $2-3k for a succession. Who pays for that is negotiable. It can be paid by you, out of the proceeds of the sale or by you in addition to the amount you offer. I normally consider it a closing cost that is not a normal closing cost and it comes out of the seller’s proceeds at the closing.
Liens against the property are only part of your concerns. Judgements against any owner/heirs is another concern. That’s why you just need to get it to a title company/attorney and let them answer those questions for you. Be prepared that it might cost you $500-600 to find out that you have what will cost much more than the average numbers I stated above. You may not be willing to risk or able to negotiate that higher cost with the seller.
The person you talk to and get a contract with, can’t close the deal without the succession being completed, but you need a contract to start the process. Whoever you deal with, make sure all money changes hands through the title attorney.