Have you taken a look at the Themes and Apps sub-forum? There are mods which allow you to do this.
But here's some sound advice, before changing anything, make sure you take a backup. And it goes without saying, follow the instructions clearly to avoid mishaps.
Swyped from my SE Xperia arc (LT15i) using Tapatalk 2
SE T300→T610→K700i→W810i→W950i→W960i→K770i→W995→Xperi a arc→Xperia ZL
+ Google Nexus 7