Disassemble as far as you can, clean with gun scrubber, lube completely with Break Free (soaked shaving brush), assemble quite wet. Don't worry about attracting dust/dirt. This gun needs to be fairly wet with Lube. It will function fine in cold temps wet (with Break Free). Sit in an easy chair and cycle the bolt by hand 500 times, re-lube...good to go. (yes, 500 times).
After five days in a pit with blowing dust, on disassembly, the dirtiest component was the magazine tube, be sure to clean it and lube it too.
As with any weapon, shoulder it with authority like you really mean to kill something.