Grill, clean it and keep it under 225.
To help with the burnt parts, soak them it tallow. You may need to flip your brisket over. You'll lose the bark but you can reapply the seasoning you'll lose.
Wrap the brisket in tin foil. Put it in the oven at 150 for 12 hours. Yes, 12 hours.
Check out my Instagram BBQ page, Let It Beef.
https://www.instagram.com/reel/DDVFJtvyLtv/
Good luck.