Hi ngolf. Yes I had to modify the dust cover. The bulb I used (Katana) fits nicely inside the cover and I suspect the Hikari's you plan to use will as well. But there is no room for the power supply to fit inside the cover. I experimented with an extended dust cover and I did not like the quality (very loose fit) of it. Even then, the power supply still did not fit inside this extended dust cover. So here's what I did:
The OEM halogen H7 bulb plugs directly in the OEM plastic bulb holder. See Cha's pictures and description at the start of this thread. You have to remove the OEM plastic bulb holder to remove the halogen bulb. I replaced the OEM plastic bulb holder with this adapter https://www.amazon.ca/gp/product/B07...?ie=UTF8&psc=1
. It looks like the same one Cha used. The new LED bulb is mounted to this adapter.
I then pulled the two wires that connected to the OEM plastic bulb holder using the technique explained by Cha. I drilled a small (about 3 mm) hole in the OEM dust cover to pass both wires. With both wires now on the outside of the dust cover, I reconnected them to the OEM plastic bulb holder on the outside of the dust cover. Essentially, I am now using the OEM bulb holder as a female plug for the LED power supply.
I plugged in the LED male power supply into the female plug of the OEM bulb holder on the outside of the dust cover.
I then drilled another hole (about 6-7 mm) in the dust cover to run the cable from the power supply back to the LED bulb.
So after doing all this, I end up with the power supply and OEM bulb holder on the outside of the dust cover, with 2 holes in the dust cover. I reinstalled the dust cover and applied clear caulking around the holes to keep water out. I tied down the power supply using a tie wrap.
Hopefully that's clear. Ideally, I would have taken pictures of this when I was doing it but it's all done now and I'm not taking it apart again (it is extremely tight to work on).