Info 2 Things to do before sending phone to Sony Repair shop

I will be sending in my phone for warranty repair, and wanted to know what all should i do before i send it in. It already has stock software installed by PC companion, and also the kernel which comes with PC companion. Is there anything else i need to take care of before sending it in?
My bootloader is locked, i have rooted the phone before and was using the Black edition rom.