I found the easiest way to get the cables through was to baby powder up the cables and bars. Attach the pull wire/line around ~4-6 wires and tape the other wires facing up the factory wire sheathing to stop them from binding. Loop the pull cable a couple times around the pull wires but keep the pins facing towards the exit (else they will bind and break)...Give it a good steady pull - if it binds feed it back through and ensure that you don't have any cables bending over.

I know there are probably 1000 other ways, but was able to do this on the first try. I have had problems on cheap drag bars (bad welds and overlap) and this was the only way I was able to get it to work.