Nexus one update 2.2 help... confused

[Guest mariec789]

Model : Nexus one

Firmware: 2.1-update1

Build: MoDaCo Custom ROM r14, SSH

question from a very confused Newbie sorry to anyone if I am repeating but read so many forums and still non the wiser.

I received a OTA update for froyo 2.2, after reading reviews before I attempted to download I was getting very excited,

A:system recovery build

RA Nexus v1.70

E: No signature (411 files) verification failed.

Can I do the update manually?

If there is ways to do this is it possible step by step instructions?

I do need the phone unlocked as I am on a spanish network. (Dont know what network it was originally)

Loving the phone and dont want to break it so soon

any help would be appreciated.