Hire an attorney. This is one thing you do not want to have any mistakes.
Would your daughter's father be willing to sign over his parental rights? If so, that would make it a lot easier. You might have to sweeten the deal for him by forgiving the arrears owed, but I would imagine it would be worth it. If you received public assistance of any type since having your daughter, however, you probably won't be able to offer to forgive the arrears.
How long has it been since he's paid support? The longer it's been, the better. You might be able to get his parental rights terminated for abandonment if it's been long enough. I'm not sure how long that would be in MA, so HIRE AN ATTORNEY.
Oh, and the most important advice: hire an attorney. Seriously. This is to make your DH your daughter's father. You don't want any mistakes, and you want it to go as smoothly as possible.