Hi guys I need some help. I want to replace the preamp valve in my Eden Metro. I sent a mail to Eden asking if it was a something a user could do and got the reply "Yes it is" with no hints on how to attempt it. So my question goes to all the Metro owners (or people with the knowledge). How do I do it ? I want to avoid undoing the wrong screws and such like. I'm not big into undoing electrical boxes but if it's simple why not. Thanks in advance for your help.