I'm a college student who loves martial arts, especially military styles (Krav Maga, Systema, etc). I have a difficulty in finding partners to practice with, since a lot of these styles require two person drills. Any suggestions on how to practice or train in these styles by myself?

Partner training is required for movement refinement (putting combinations movements together), Proper depth penetration( closing the gap) and neutralizing the enemy's attack, also for target acquisition.
But, On a BOB or a SparPro, or even just a heavybag, you can work those same combinations with a lot more speed and power without worrying about hurting the partner.
Also doing your PT. Simple calisthenics (Mountain Climbers, Squat Thrusts, Push ups Pull ups, Dips, Sitting Knee Bends/ Ab cruches, dry land swims for the low back [It is still part of the core muscles.], every other day do your Power lifts(Flat Bench Press, Bent Rows, Military Press, Deadlift, Squats, and Barbell Curls). do you runs, the 400 meter and the two to three mile.
if you wish to perform the combinations almost like a kata. Just learn to think ahead incase murphy throws a wrench in.(Learn to change up the combo, when needed.)

Good Luck macavity166

Joel

I recommend just doing bag work. Sparring with a friend is very good at higher levels when you already know what to do and what not to, without this you may develop poor habits. I train in Krav Maga and find the Bas Rutten MMA workout tapes are great for practicing on your own.

And BTW systema is not really a military system, it is marketed as some secret KGB thing, it is as useless as a Nun's T*t's
The Russian Military uses a combination of a few H2H systems, and a lot of Sambo, believe it or not.