Some of you may be well versed in the Nexus One update process by now, but here it is again, courtesy of Android Central:
-Download the update from [down below].
-Rename the file to update.zip. Note that if you’re using Windows, just rename it to “update” (no quotes, of course) because it’s already a zipped file.
-Copy the update.zip file onto your microSD card.
-With your Nexus One off, hold down the trackball and press the power button.
-You’ll be booted into a white screen with three Android robots on skateboards. Select “Bootloader.”
-On the next screen, select “Recovery.”
-Your phone will reboot, giving you a picture of the Android robot and an exclamation point inside a triangle.
-Now press the power button and volume up button at the same time. It could take a couple of tries.
-Now (using the trackball this time) choose “Apply sdcard:update.zip” and let things run their course.
Let us know how it works for you!