how do you win a democratic party primary?

First you have to understand your local democratic party.  What is the
base?  What are the voting trends?  How often has non establishment
people won, and what sort of campaigns did they run.  You should also
make sure that you have a reliable staff.   No one can win alone.  and
get prepared to work harder than you ever have.   no resting until the
day after victory!

Run to the left of your democratic competitors and then lose the
general election.  At least that is the way it has worked lately.