Originally Posted by IDRIDR

You may have two screens. Good.
Yes, the arrester needs to be removed to get to the quiet core. Take out the three allen head bolts, remove the cap, and the screen and core can be removed or inserted. Very easy.

Malves ^ has it right on the chain guide. I suppose the guide is supposed to help keep the chain from breaking into the case in the event of a chain break. I removed the plastic cover and kept the metal guide, but I think I needed to use some shorter bolts so if the originals are in the bag with the plastic, but the metal guide is attached where it should be, that should be okay. The plastic guard removed from your bike has a tendency to collect mud and debris and it gets all jammed up against the chain and countersprocket, which is why my guard is removed.