The first step of course your phone has been hacked, if not please read the previous tutorial on how to hack symbian s60v3 and v5 without cert and key.

This modding is no need to disassemble your phone system is sometimes a headache because if there is a mistake make you headaches.
How to start modding start up tone on your symbian s60v3 and v5,after you hacked your phone you must be installed:

• Phyton to your phone
• Start Up tool

when phyton and start up tool already installed,open the start up tool and edit your tone from your phone or download here for another funny ringtone,after you have choose the tone last step is switch off your phone and switch on it back taraaaaam,your start up tone has been change with your fave tone,but dont change the start up tone with long tone because it will be make your phone late to opened because its must be wait until the tone finish and your phone is activated,so just use a short tone between 4 till 7 second only.