Just get the framework.jar from the /system/framework folder once you have your ROM installed. It isn't neccessary to do it in advance.
Y have taken the framework.jar from the cooked rom I have followed the steps but there is no internal folder inside out/android/.
There is a path \out\com\android\internal\telephony\gsm but then there is no GSMServieTracker.smali. I have founded a GSMServiceStateTRacker.smali but I cannot find the lines of code inside.
Also there is 3 more files in the path GSMServiceStateTRacker$1.smali GSMServiceStateTRacker$2.smali GSMServiceStateTRacker$3.smali but again I cannot find the lines inside.
I am talking about a HTC desire just to clear confusion, so I guess I will hace to stay with my Roaming, It´s a pain because I am living close to the border and sometimes is taking the foreign country network and giving my a nice extra charges on my bill.
Thanks anyway guys.