Help with E1086L band change

[lsuarez1977]

Hello friends,
I have an E1086L wich works in 850/1900Mhz. I want to change the operation bands to 900/1800Mhz. E1086L models are dual band, they can work in 850/1900Mhz or 900/1800Mhz.
If is it possible. What i must to do?
Is it possible this band change through a full flash?
Is it neccesary to do any change on the mobile hardware?

Thanks in advance for your help,

Regards,

[lsuarez1977]

Please, anybody know about this issue?