Originally Posted by
adlai
... routing through the bike frame, so I don't want to remove it.
I have a bike with a thru-frame rear brake cable routing. Nearly the entire length of housing goes through the top tube. The way I replace the housing is to leave a headless brake cable in there all the way through while pulling out the housing. Then reverse the process to install new housing. I keep the headless cable in my tool box just for this operation.