Rear brake line replacement tips

[Smudgemanuk]

Hi all,

Soon I am planning to replace the rear hard steel brake lines on my z

However, having had a look at them, the line traversing the rear subframe looks rather complex and I am thinking it will be a challenge to do in situ.

So I am looking for some tips and advice on how to proceed.

Is using flexible braided lines the thing to do?
Is it only possible if you drop the subframe?
Any other tips would be much appreciated

Thanks