Quoted from Wickerman2:http://www.heighwaypinball.com/update1.41.zip
You should email support for the specific instructions before you do it---there's a service bulletin with exact walk through.
I haven't had any of my messages to support responded to so far, even after Andrew asked me to email him directly. I understand things are busy, with trying to get Alien out, but come on guys, at least respond to my requests to support.
I've also got a lighting issue and would like to code update.