You need to do this on Der Riese.

First thing, get over 3,200 points and keep one zombie alive.

Then open all the doors on your left, turn the power on, go across the bridge to the teleporter, then wait for the zombie to come.

Then kill the zombie and run into the very back of the teleporter, which is inline with the line.

Then turn around and crouch.

Note 1: you do have to do this before the other round starts.

Note 2: the dog levels take 2-4 minutes.