I have just received my built up Giant Defy Advanced 0 with Di2 posted to me as an insurance replacement for my damaged Madone. Problem is the grommets aren’t installed though they were sent to me. So I want to install them but unsure how this is done, do I need to pull all the wiring out and start again? Wondering whether to just slice into the grommet so I can put it in place around the wire without messing with the cabling. I think they should be installed to stop water getting in and to protect the cables from rubbing against the frame holes.