I am a resident of Nevada and I work for the military in California. I paid California income taxes and how do I receive that tax money back since I'm a nonresident.

Were you active-duty military or GS or contractor?

yes I am a GS federal employee for the military.

If you worked in CA as a civilian (GS employee), you are subject to CA income tax on those earnings. The military exclusion only applies to active duty military. 

The Service Member Civil Relief Act states that an active duty member is not considered a resident of a state unless it is his SLR.

https://ttlc.intuit.com/replies/3300147