My partner and I take care of her 2 sons, However the father has paid child support maybe twice in the last 11 years. He occasionally surfaces and has his wife contact to get the boys but then disappears again. They don't get birthday calls or gifts and christmas is the same. He has 3 kids with his current wife and he tends to take care of them except on one of his frequesnt disappearing acts. She wants him to just give up rights so the boys can move on but we have no idea where to start

https://www.askmehelpdesk.com/family-law/signing-over-rights-read-first-116098.html

No one can just make him give up his rights. Even if he wants to, it's not an easy process. Read the link to the sticky above. It answers a lot of FAQa about giving up rights.