I have some things for you to consider, before you sign your child's life away.
One- in most cases it will not remove your
child support obligation.
Two- my husband went a year without seeing his daughter, and it tore him up. We were able to beg and borrow money, putting us into debt, to force visitation with his daughter. Despite being in contempt in several different ways, she got a "now now, don't do that". Although my husband now sees his daughter regularly and his ex has chilled out. We believe it is because her new husband is a pretty decent guy and keeps her in line. I cringe at the thought of her with some power-trip jerk or if she had stayed single and un-medicated (oh yes, medicated).
Our baby daughter now loves her big sissy, and my step-daughter is a smart, sweet and beautiful child that we love to bits. She loves her little sister, and she knows that her dad loves her and is willing to fight for her (she heard her mom's side and parroted to us- without bad-mouthing, we corrected a few things she told us). It breaks my heart to think that she would hve to grow up thinking her dad "didn't want her" (which is what CP told her).
Three- my father gave up on his first 2 kids from his first marriage. They grew up with all kinds of poison from their mother saying that he left her (lie, she left him and moved 1000 miles), and wouldn't pay child support (she told him to stay away OR she would file for child support), and that he was living up the rich life with his new family and kids in Florida and didn't care about them. THey grew up hating him. Literally hating him.
We have had contact with them, at a point we tried to work things out after they became adults- and after several years of my dad helping them financially for about 7 years (he has money now, but not when we were young- we shopped at food banks), he finally said "okay, you should be well off enough to take care of yoruselves now", they turned on him. It was horrible, and it tore my dad apart.