1. Download the Android 2.2 firmware for the Nexus One – here is the link to Download 2. Rename the file update.zip and copy it to your microSD card via USB. [Note: make sure the file is named update.zip and not update.zip.zip.] 3. Power down your Nexus One 4. Hold down the “Volume Down” button as you power the phone back on. 5. A screen should appear showing your phone’s system searching for various files. Scroll down to “recovery” and press the “Power” button. 6. When you see the triangle with an exclamation point symbol, press the “Power” and “Volume Up” buttons at the same time. 7. From the menu that appears, select “Apply sdcard:update.zip.” 8. When the screen displays “Install from sdcard complete” select “reboot system now” and wait for the phone to power back up.