Upgrade to 5.1.1, but keep root AND user data

Hey guys,

quick question. I have a 5.0.2 z3c rooted with dual recovery and would like to upgrade to 5.1.1.

However, I don't want to lose neither root access nor my personal data. How to correctly dirty-flash a prerooted flashable.zip from recovery?

Also when creating the prerooted flashable.zip with PFRCreator, do I need to use the same Recovery package as I have installed or can I upgrade the Recovery on the go?

Edit: Sorry, wrong Sub. Please delete