Go to Cupinook 12 C, Zetford Horizons
There is a spawn of 3 skimmers there with no turrets unless you land in your SRV. Lower your ship to about ground level and blast the skimmers from above. Save and exit the game and reload it. The three skimmers will be back.
The skimmers won't shoot you in your ship, but if you get too close they can significantly damage it if they run into you. I used fixed lasers but I'm going to guess that dumb fire missiles will work better.
*authors note*
- If you can't hit things that aren't targeted from your ship ignore this solution and get in your SRV.
- You will lose rank in that system, get a bounty, and will earn 0 in game credits for doing this.
- I created this with the intent of being the fastest and safest way to do this achievement. If you care about certain criteria in the game such as making money or that your faction rank goes down, then don't do this.