Originally Posted by Ult1ma Weap0n
Well we finally know an easy way to get turtle soup achievement. Start a solo game then sign in a 2nd controller. Don't touch or move player 1 (your gamertag) let the first foot soldier kill player one and dont press any buttons on the first controller so you dont respawn. Now get to krang with player 2 only. Beat krang down untill he's almost dead, now respawn player 1 and let krang hurt him a little bit and then beat krang with player 2. The trick is to be at shredder with player 1 in low health. Now let shredder kill off player one, remember not to move the player one controller at all. Once player one is dead beat off all the shredder clones (doesn't matter if you're turned into a turtle) once the real shredder loses his helmet respawn player one then beat shredder and his new helmetless clones with player 2. ACHIEVEMENT UNLOCKED. Remember dont move or kill anyone with player one and shredder has to kill you once.
Thank you, read this post specifically and it worked, very much apreciated, so I can vouch that this works for sure.