This is the fastest way I got the achievement, if you have two controllers, go into a local match for Process and choose whichever side you want. Set aside the controller that is going to get this achievement. The other controller will be the one you will be committing suicide with.
If you start in front of the stairs, go forward just a bit and go right down the stairs, there will be grenades there, toss one at the wall and die.
If you start in front of the bridges, go forward and hang a left, you will see three barrels in close proximity and grenades just in front of those, toss a grenade at the barrels and die.
The whole process, including intermission, should take 1min 40sec if done right. Enjoy your achievement when you get it.