How to configure phone number in LG l7 (P-708) i can't setup the phone number in:


Settings -> About phone -> Status -> My phone number


 

How i can change it in the LG L7 P-708?

It has installed Android 4.0.3
What you are trying to set is the MSISDN number on your SIM card. This can be quite difficult to do on Android. This site has a post detailing how it can be done on various phones (including non-Android) which if you have access to another device is probably the easiest way.

If you don't have access to another device then you could try the myphonenumber app. This is very flaky and only works on certain ROMS/devices.

The other option is to contact your operator as I believe this is something that they can set OTA, although most don't seem to know anything about it from my experience.