How to deduct milage without putting my car into "service"

How to deduct milage without putting my car into "service".  I am a remote employee and do not have an office.  I do not claim my home office as its proven to be more of a pain then it is worth.  Anyway, I had a 4 month period at a new job where I had to drive a lot to get to training class.  So I wasnt driving to between home and an office....but rather from my office to training.  Can I deduct the milage?  if so, how