The key of course would be to isolate and sweep the station block by block, using reinforced barricades, sentry guns, tripwire mines, etc. to isolate or block off the aliens access to vents that they could use to go around the main thoroughfares. Channel them into kill zones and use the marine's squad tactics and firepower to finish them off. Or at least that would sound good on paper anyway...
...Of course, the wild cards are always going to be the civilians themselves who appear to have gone bugfuck (no pun intended) crazy with the xenomorph threat, corporate meddling, runaway androids who should be destroyed on sight, and the station marshals who seemed to be acting cowboy and didn't seem to really give much of a damn about the civilians other than eliminating the alien threat. The Marines would essentially have to institute martial law on the station, and tell them they're there to help, but they can only help if the civilians cooperate.
Barring that, or anyone who refuses to cooperate? Either detain them, or shoot them.