I'm sure a long time ago I saw a guide on here about how to put your rear brake line though your swingarm and were to drill etc. But I can't find it anywhere if someone has the info would be great also is there any down sides to doing it? Cheers

Not sure about the guide on here, but if you look on the underside of the swingarm there is a circle near the rear where the brake like needs to come out. this has to be drilled at an angle (towards the front of the bike) but large enough to get the banjo bolt/tightner through. you can then use a 12mm rubber electrical grommet over the brake line to plug the newly drilled hole. I have a bare 35 swing arm in the garage with this done i'll try to dig it out tonight unless someone beats me to it.
No real benefit from doing it apart from making the rear end look tidy.

Great thanks for the help ☺