Left 4 Dead

This Can Be Done by simple getting the white gas canisters, throw it the tanks way and shoot it to make it explode making the tank temporarly stunned earning yourself an achievement :P

Edit: it seems that some crash course achievements are glitching for some people, if this happens it's quite unlucky :( can't wait for them to fix it because I can't get slippery pull :(

Edit: for people who for some reason strugglewith this here's a videofrom RoosterTeeth (they are awesome :P)

Since the other solutions don't mention this, you can get this using a pipe bomb, too. In the generator sequence, the first tank came from near the entrance, climbing over the fence; the second tank came from the low roof of the building connected to the garage. In both cases, the tank took quite a while to climb over/down, giving plenty of time to judge distance and aim your toss.

Known explosion types are pipe bomb and propane tank, both methods work, as long as the tank is performing his stun animation after being hit with the exlposion (a backwards stumbling and dizzyness).

This can also be boosted on a versus match, but it must be a local server (not the standard dedicated server match) match by either setting up a system link game with 2 controllers or performing the "rapidly tap A on the start match option" method.

Just be careful if you're trying the latter, as if you press A too fast, it may crash your Xbox, requiring you to power it off and back on again. Pace yourself, try it for a second or two, slow down, let it search for a dedicated server for a second, cancel, hit A rapidly for a couple of seconds, slow down again, etc.

I used the basics of the first guide here, but I had to help myself out a bit.

I started the campaign on normal, grabbed the first propane tank I found and carried it out to the court yard with the first alarmed car. Then I waited for the Tank to show up and incap one of the bots.

Then while the tank was pounding on the incapped bot I threw the propane tank at it's feet and started shooting until the propane cylinder exploded.

You might have to do it a few times to get a Tank at the right spot, but this should work at any part of the level, as long as there is a propane cylinder and a Tank.