From Stock EPF21B to FRF85B

[Guest pkbx]

Hello,

I have seen a few guides floating around the internet on how to do this, but given i am a complete newbie i was hoping someone would explain to me what is happening at each step, as i would be much more comfortable understanding the process that is going on rather than just blindly following instructions (so if something does go wrong as least i might understand what he problem is!)

At present I am running a stock, locked N1 running EPF21B on Vodafone UK..... Given it has been publicly stated that Froyo will not be coming to users on this build for two weeks at least (and even then tethering may be disabled)...I have decided to unlock my bootloader....

So....

I have installed the Android SDK and got fastboot working....My key question is this, after I unlock i need to flash a new recovery image (because I assume the EPF21B recovery image will not allow flashing of the FRF85B rom)...Can this be the RA-CUI or does it have to be a version of Eclair that has shown to support the Froyo OTA update (i.e US builds such as ERE27?)

Thanks..