If you are like me, and are going through your first run on Master Difficulty, then this can be a pain.
HOWEVER, there is an easy solution for taking care of the reapers WITHOUT glitching the game.
On the very first platform is a building. Inside the building is an L-Star submachine gun. That thing will rip the reapers apart insanely fast, even on Master Difficulty. So if you are like me, and struggled to survive with the Spitfire and the DMR, get to the building, trade the Spitfire out for the L-Star, and cut through the reapers like it is easy mode
Questions, corrections and neg vote justifications below.