[Q] Flash new ftf while keeping root? topic

Hey,
I have a rooted Z3 Compact (D5803) with locked bootloader (via the gfrieroot hack).

However now I still have this old fw and I want to update to the latest KitKat FW, 23.0.1.A.5.77, according to this list:
http://forum.xda-developers.com/z3-c...d5833-t2906706

So now I'm wondering how can I do this, with keeping root?
TY

PS:
Before you ask, I want to stay with KitKat until Lollipop is more mainstream -> less problems.