"Now what do I do on the tax return for the sale."

No one on the internet can research the rest of this, even if my description is close to reality. Examples:

Whoever was handling this sale should have determined there were Real Property legality issues. If the deed or title showed the deceased, then this is sold as a separate asset to the other party.

If the partnership share is sold, it doesn't include land it doesn't own. That is going to affect the FMV of the Partnership.