Originally Posted by athankar75
So this can be only with root acces, right?
No you don't, but you need to get CWM and flashable deodexed files for your firmware.
Get the correct flashable deodexed files and flash in CWM to deodex your system apps. Then you can bring out and edit the Contacts.apk (or whatever apk name, I forgot) using apktool. There should be image files of the icon you don't like. You need to extract and recompile framework-res while doing this too.
Find the guide somewhere in this forum or other forum (similar things). At least these are what I did to modify SystemUI.apk previously, the process is similar.
Device: Samsung Galaxy S II Plus (I9105P)
ROM: Unofficial CyanogenMod 11 (4.4.2) + Tweaked LCD Density (140)