Assignment contract : How to handle this owner finance deal

[Robert L.]

I've got this real sweet owner finance deal negotiated with my seller. I am paying him $25k now and $22k in 18 months. We are about to sign the paperwork when he tells me that he needs to use his assignment contract. I found out that he is actually assigning a contract that he has made with his uncle. He has equitable interest but does not have the deed yet. He says that my contract will satisfy the terms of his deal. In other words, my $25k down payment will take care of his uncle. How do we set this paperwork because I also plan to assign my owner finance deal to my end buyer. For example, does HIS assignment contract need to contain the wording that he'll get paid the $22k in 18 months? And then MY assignment contract adds a $5k assignment fee (I'm trying to make a $5k assignment fee for this). Can the title company do this? Thanks Rob