There's really no 'quick and easy' solution for living/working at altitude. I was in very good sea-level shape when I reported to Ft Carson, but it still took almost a month before my performance there matched what I was doing at lower elevations. As others have suggested, lots of water, deep breathing and progressive exercise are essential.
BTW, don't listen to CoLawman; those Greeley guys are a bunch of flatlanders at only 5000' AGL.
