Lot line adjustments

[Jason Moran]

Ok folks, I need some help here. I've entered negotiations on a property that's ag/commercial and 12.5 acres with a residence and multiple outbuildings (shops). I want to sell off the back 7.5 acres to the neighboring farmer and have already discussed this with him. He's interested and the numbers are working. A lot line adjustment can be made through the county since no new number of lots is being created, (just on lot becomes bigger while the other becomes smaller). Here's my concern: How do I secure/ensure that farmer 2 is going to actually purchase the back 7.5 acres once I've purchased the entire property? I don't want to get into this and then have him back out and leave me stuck with 7.5 acres I don't need.