Need help rolling back firmware (Xperia z3 D6603) topic

Hi was wondering if I could get some assistance rolling back firmware on my Xperia z3 D6603 im new to this so any help would be greatly appreciated

Looking for help with installing firmware 23.0.A.2.93

Currently using...
Firmware: 23.0.1.A.5.77
Kernel Version: 3.4.0-perf-g1b1963a-02930-g23f7791 Builduser@Buildhost #1 Tue Nov 2511:03:01 2014
Device Model: D6603