
According to defence-blog.com the Army has awarded AM General another $51.3 million to modernize the HMMWVs. This contract was announced by the Department of Defense (DoD) this last Monday.
According to the DoD all work will be performed South Bend, Indiana. Which is estimated to be completed by end of 2019.

How can i be one of the HMMWV mechanic
Buy one and you can work on your own :). Happy to set you up with a HMMWV