There is a good DIY thread on plug installation over at MBWorld that has been linked to before. I'd give credit to who pointed me to this thread originally, but I didn't save that, I only saved the link.

http://forums.mbworld.org/forums/sho...d.php?t=216940


The linked thread is for a C Class, but it is pretty close to what you'll have to do for a Crossfire.

Injectors - I don't have any saved DIY's for that.