Fixing Red Ringed Xbox 360 (GONE WRONG) 

You needed the RROD code of the 3 segment RROD. 1 segment RROD might come on display, or same you need the code by holding sync and press eject. Overheating like that is because you didn't clean the old stuff off correctly, it's a super high bond thermal pad that is really hard to clean off

It’s overheating lol did you put the correct thermal paste amount on it