Hi and welcome to NICO Club!
For something like that, you'd follow all the steps in the Factory Service Manual (FSM). The EM chapter has that information. I don't have a 2015 FSM at my fingertips, but I do have the 2014 and 2016. Here's a link to the 2016 FSM EM chapter which should be nearly identical. Have a look at page 16.
http://www.nicoclub.com/service-manual? ... %20Note/EM