I would, after much effort and scavenging, construct myself a silenced sniper rifle with a scope. Over the course of several weeks, using ammo I found around and ether, I would one my one eradicate all the marines from a safe distance.
Once I managed to acquire a shuttle key card, I would take the shuttle back to my base of operations. Using a scavenged warp coil, I would manufacture a warp drive for the shuttle, hopefully successfully installing it. If time was not of the essence, I may even construct a laser or two to mount on my shuttle in case of unknown threats.
Fleeing to the closest safe world, never to return to that dreadful planet, I would live a happy life!