Cover letter for maintenance machining for Hermle

I need help with a cover letter for a machining company. I want to work for Hermle ( https://www.hermleusa.net/en/home_en ). I want to be one of their traveling maintenance repair guys for their machines. I started working on Hermles in April this year with a company called Essai. I have watched the maintenance techs  come in and out of My work repairing and doing maintenance and setting up new machines. Thats what really interest me of going ahead and applying for this type of job. I love watching them take it apart and clean it fix it put new filters in/ new lines/ new tool holders/ etc and put it back together. Or when theyre setting up the brand new machines. Ive watch them build the C22s in the back. Ive learned a lot from the guys that come in and out of my work that is helped me run these machines better. I love running the machines theyre very nice. C22s and C42s I am running at the moment. And I would like to work with a company that actually makes these machines. I have an associate in machining and project development. I also have some NIMS Certifications as well ( 1. Measurement, Materials, and safety. 2. Cnc lathe 3. Cnc milling. ). I been machining  for 2 1/2 years. What else do you need to know for a great cover letter?