Nokia 2630 firmware upgrade

[Rouxenator]

I got an old 2630 two days ago and as a basic phone is it good but when I try to use it as a bluetooth modem it reboots sometimes. I checked the firmware and it is really old so I called the repair shop I normally use and the technician said they'll upgrade it for free.

So I am wondering how easy is it do upgrade these non USB/BB5 phones ?