The service manual is available on one of the forums, you'll need to search it out, I think one of the members has it in a link to his dropbox, You can also get an alldata subscription for about 30 bucks a year. The manual is very comprehensive and very, very redundant. I have used the alldata in a professional capacity & it's very good, but I'm not sure how much coverage they offer on the VM 3.0. You also need to be very careful, the glow plugs have a tendency to twist off, leaving you with a mess, go slow on them, loosen a little, then tighten it a little, use a good penetrating oil like PB-BLASTER, keep working it back & forth & hope it doesnt twist off or strip, you can buy extractors for them if they break & also get thread repair sets if they strip, BUT, it could get into a cylinder head replacement. Use a good antisieze on the new glowplug! Sorry to bear potentially bad news. BEST WISHES!