How can i change the icons of Sony Ericsson G900 without installing any software on my phone.?

Or if required any software to be installed on my phone.How can i do the permanent hacking so i can remove the software afterwords any doesn't require any software to be installed on my phone.Changing my icons means that when i see the themes for Sony Ericsson G900 on some websites it contains icons along with visual styles son when i download and apply on my phone the visual style is changed but icons cannot.So please help me.Tanks.How can i change the icons of Sony Ericsson G900 without installing any software on my phone.?You're gonna have to check the forums for that phone. Just google ur type of phone then search for forums. I thought I knew but it was the wrong phone, or check youtube.