Destroy All Humans! 2 - Reprobed

Whilst the achievement is self-explanatory, you're going to need certain things to finish it. Specifically, the Ion Detonator (gained in Albion, so unless you've managed to sequence break, you should have it already) and the higher-tier jetpack upgrades. As you probably guessed, use the jetpack to reach the next highest point, stopping to let it recharge occasionally. The last leg of the climb is too high for your jump pack, so you're going to have to launch an ion detonator at your feet as you jump, then detonate it before activating your jump pack to get the required lift. You don't have to land on the tower at the end, just be within close proximity to the highest point of the tower without being underneath it.