Here is my guided video, but for those who want a written walkthrough:
1. Load the first campaign area: IPSILON.
2. Load the first mission.
*You may have to beat it the regular way the first time.*
3. Delete the wheels on the backside.
4. Attach 7 balloons to the top of the vehicle, don't try to make it bigger.
5. Start the level. The vehicle will drop, then start flying.
6. Speed up the time in the top left by sliding the bar to the right.
In 30-60 seconds, the vehicle will hit a max height, freeze, and drop. Achievement is yours!