[Q] How to allow access to /system on Z Ultra C6833? topic

How do kind sirs/ladies.

Basically I'm having trouble finding out how to allow apps (and xposed modules) to have write access to the /system folder. The device is otherwise rooted, and is running stock Xperia firmware 4.4.4. Ideally this would be done without a PC as mine has bit the dust, but if its the only way then hit me. (Figuratively please, I bruise like a peach)