In Forge, at the first camo spot in Highground is a ledge that resembles a triangle. Go into Monitor and push into the ledge to be killed by guardians.
In Forge mode, select either Sand Trap or Foundry and spawn a Grav Lift, then a Fusion Coils on top of it. Set the Fusion Coil respawn time at ten seconds and let them get shot into the air. When they land, they will explode. Get under them when they fall and allow them to kill you. If done correctly, it will say "Killed by Guardians". Do not let your opponent shoot you or it will say that they killed you after you hit the explosives.