Sorry, haven't been to this site for a long time.
I did not flare the end, as I kept 1 of the 2 flares that were already there. It's been fine ever since.
NO! I did not remove the bumper I do have black plastic covers perhaps where foglights can go. I simply detached the passenger side one from below and had excellent access!

Here's the main post I made about this right here:
https://acurazine.com/forums/first-g...-money-951344/

Hi I have a 2004 TL and I’ll be replacing the return lines soon. I’ve already replaced the pressure side which was a chore in itself. What I’m curious about is purchasing the Honda line and cutting it down. I don’t see the procedure you mentioned. Can you tell me the part number and where exactly you made the cuts? Also, did you need to flare the cut end? And lastly, did you remove the bumper to complete the service?