Would like to know how can I reprogram my Nokia 6610

Hi I have been reading around a bit and got pretty interested is it possible to program it I mean the operating system of the phone not the Java! Anywayz if it is possible can you guys out there please gimme some links to learn how to do this and for god sakes stop giving links to sites to unlock, upgrade the firmware, and other sites that teach me exactly the same things!! BTW I don't know much about assembly so hope I can get around there abit too if it is really needed to program my phone thanks a lot in advance :)