If you managed to complete the game without unlocking this trophy, try the following method:
Use Chapter Select to load up Chapter 3 - Borneo and select Very Easy difficulty. Play through chapters 3 and 4, and you should unlock this trophy fairly early in chapter 5. There is very little platforming in these levels for you to die on. Also, do not restart any checkpoints.
Note: The trophy will unlock as soon as you get the 75th kill without dying or restarting a checkpoint.