轉載：http://www.xanh.co.uk/ways-to-update-your-device/#more-135
There are few methods of getting the latest firmware onto your device, most of them require one ingredient: correctly signed (incremental or full) OTA (usually: update.zip) file. Once obtained we can start manual update process. Usually various ODMs provide more than one way of achieving this goal.
1. Use default client
Usually each device has its own update client. From time to time this application in background pings the ODM server in order to find if there is a new update. The main drawback is stage roll out (when only part of user receive an update at the time). This means that you might face arming yourself in patience and waiting for your turn.
Advantages: get original firmware update + seamless customer experience
Drawbacks: might take a while to get update (while others already have it)
2. Recovery mode
Once you get the latest (still fresh) update file into your hands you can start manual process of updating your device. Recovery itself gives 3 options (most common ones).
a. Sideloading
This option enable special ADB protocol allowing to send update file directly from your PC. Once option (‘apply update from ADB‘) is selected you can transfer file from your machine using following command:
adb sideload /update.zip
Once transfer is completed the update process will start.
Advantages: Update directly from your computer
Drawbacks: File transfer from PC might take a while + might require additional drivers + require for ADB
b. Update via SD Card
Simply copy the update file onto the SD Card, insert it into device, select option (‘apply update from external storage‘) and then confirm file selection and voila – job done your device is updating. What if your device does not have SD Card slot (or you don’t have SD Card)? See option a.
Advantages: Simple alternative if ‘Sideloading’ setup is troubling
Drawbacks: Device has to support SD Cards
c. Update via cache
As a root you could push an update to a location on cache partition. Then use recovery to apply this update.
Advantages: It exists (?) as alternative if others fails (not available)
Drawbacks: Require ADB and root access
Check my other post if you face any problems with updating your device: OTA update recovery errors