TP2 with Sprint - need info!

[matyana]

Sorry friends...to make it more simple !
My phone Radio version is: 1.96.00WF (which means its LOCKED)
but as already mentioned....this is CDMA version and was actually issue through SPRINT US network. But At present i am using in UK....and it works perfectly fine with all GSM netwroks....but its Radio is still 1.96.00WF.
The reason xplain the whole situation is, because on some threads I have seen that it says to unlock the Radio version to WU and then you can upgradte to Custom rom of WM6.5.
Now in short guide me through:
Can I upgrade straight away just by installing the desried Custom rom of WM6.5 or do i still need to unlock the Radion version to WU?

regards