Enroll the AI at law school and let it get a degree? Reminds me of a whimsical shower thought I had once.... Create a business that owns itself, and write an AI to run it. Owns its own bank accounts and everything. Maybe the business is just selling stickers online or something equally lightweight, but give it all the legal status of company. But a company with zero human owners or any human employees. Make it a rebuke of the "corporations are people" idea. Just a zombie out there selling products/services, and making money that no human can ever touch again....
If it sounds crazy/stupid, remember - I did say "whimsical shower thought" ;)