This achievement is best to get with a troll or an elf. Basically just save your money until you have enought to buy the rockets (Rocket launcher is 5,000 and each extra shot is 1,000. I usually wait until I can have at least three shots, but that is up to you.) When using the Rocker Launcher either Glider and/or Smoke is A MUST! Wired reflexes is also helpful, but is not in any way required. Smoke is useful when you get very close to someone. Just shoot your rocket at their feet and smoke! If you are using glider fly up into the air and shoot the enemies below you. This achievement WILL take time (I don't even have it yet...) but be patient and you will get it.
Side note: Pay attention to your reticule when shooting the Rocker Launcher. Because of the bloom in Shadowrun rockets can be terribly inaccurate.