Android: extending PhoneBase?

I know it is possible to use TelephonyManager to get information like: service state, device ID, Sim Operator, etc... Is it possible to edit some of this information?

Couldn't find .set() functions on Android.com documentation but I've found the GSMPhone.java source code which includes functions like .setNumber1Number() (used to set/edit the number?).

I basically want to know if it's possible to edit the phone number located on Sim card (Settings->About->Status->My Phone Number).

Appreciate any answer, even a simple "NO", if it's indeed impossible.

Thank you!

Is it possible to edit some of this information?

Only if you write you own firmware.

Couldn't find .set() functions on Android.com documentation

That documentation is for the Android SDK, for developing apps that can be distributed via the Android Market and similar venues.

but I've found the GSMPhone.java source code which includes functions like .setNumber1Number() (used to set/edit the number?).

That is from the Android source code. If you write your own firmware, you can use those methods.