You can get this during normal play by driving off a cliff and landing on top of an enemy tank of any tier. The weight of your tank will crush and destroy the enemy (you need to survive for the achievement to pop). Some tanks are better than others but generally you will have more success with tanks that are reasonably fast but also heavy (for their tier).
Good maps to try this on are from the high ground on Abbey, Cliff (obviously), El Halluf, Karelia, Komarin, Malinovka, Mines, Mountain Pass, Pearl River, Sacred Valley, Sand River, South Coast and Westfield
Here are some examples of how to go about it:
It's possible to do this in any tank if you squash the right enemy but it's generally not a good idea to try this on heavy tanks (unless you're in an even heavier tank) and best to go for anything else (light, medium, TD or artillery but the lighter the better). Some examples of good tanks for this at lower tiers are:
Pz. II or III (most variants)