I VISIT THIS SAME PAGE AND I FOUND THIS:
You can change GSM frequencies to 900/1800 by entering the enginnering model. Following the below steps:
enter menu and press 048263* quickly, then you will enter the secret engineering menu
under "Opcode"
input 10*0*3 for GSM 900
10*0*4 for GSM 1800
10*0*5 for GSM 1900
10*0*6 for dual band GSM 900/1800
10*0*7 for dual band GSM 850/1900
WHAT? IS ENGINEERING MODEL?????????