I'm not too sure what you mean. Do you want to remove your mobile network providers firmware? for example Vodafone's screen etc?

Some network operators install their own version of the phones software. I'm guessing you want to remove this and have the Nokia default firmware.

Have a look at this forum tread, it explains how to do it with a Sony Ericsson phone. But I think you can use the same software to change a Nokia. Anyway have a look. The client you will have to download and use is called Kulan Kendi (you have to pay them unfortunately).

http://www.esato.com/board/viewtopic.php?topic=141900&start=15#post1925611

If this tread does not help you, do a search on Google for "Flashing Nokia Phones" or "Changing a Nokia Firmware", I'm sure you'll find something.

But becareful when updating and/or changing a phone firmware, back up everything first!!

Sorry I can't be more specific.