Whenever we talk updating our phones, we inevitably talk about "manual updates." And that leads to the inevitable questions, "Is it safe?" and "How do I do it?"
Manual updates are just like over-the-air (OTA) updates. Only difference is that instead of letting your phone download the update from a server somewhere, you download it yourself, move save it to you phone's SD card and then manually start the update process. In an OTA update, the phone does all this for you. But the big difference is that there's no waiting with manual updates.
In the video above -- edited for time purposes -- we walk you through manually updating the Nexus One to Android 2.3.3 Gingerbead. And note that this is for a stock phone -- unrooted, stock recovery, the whole nine yards.
The general process is similar for most phones, though you'll want to follow the instructions for your specific device. And as always, if you have more questions, hit us up in the Android Central Forums.