Aside from fitness training where you are, there isn't really a feasible option for conditioning your body to high-alt, low-O2 situations without being in one (or in a special training facility that has the ability to do that).
The only way your body will get used to receiving less oxygen per breath will be to exert yourself in that situation. This is why sports teams travelling, particularly to Denver, usually go a week in advance and train leading up to the game.
All you can really do is make your body as fit as you can possibly get it before going. The better shape you're in, the easier it will be for your body to cope.
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Hi. I'm Kyle.