How do I get our name off a land contract?

Basically, my husband and I and a friend did a land contract with the friend’s dad. We (my husband and I) asked to have the septic looked over to make sure no issue such were there. Well, there were. The friend and her dad didn't want to have it done. Fast forward a year and my husband was diagnosed with cancer. We no longer could take care of the property and chose to move. The friend still resides there. What do we need to do to get out of this contract? Can we sell and give him the payoff or whatever? The agreement was only for 3 or 4 years. If we can't sell, does the friend need to buy us out? Not sure how it works. Thanks.