How to Install Android 2.2 Froyo on Motorola Defy: Complete Guide
First of all, you need the Android 2.2 Froyo ROM for your Motorola Defy. You can download it here.
Download Android 2.2 Froyo for Motorola Defy
It is a Nandroid backup for the Defy. You can use it to install Android 2.2 Froyo on your Motorola Defy. Copy it to your phone's SD card and then disconnect the phone from the PC.
To install the ROM, you will need the ClockWorkmod ROM Manager.
Start Android Market on your phone and search for ROM Manager. Install the Clockwork Mod ROM Manager. Note that your Defy must be rooted before you can install ROMs on it.
Click on ROM Manager and then take a backup of your current ROM if you want to. Select Manage and Restore Backups.
Select the Nandroid Froyo backup you just copied on the SD card and restore it. Wipe Data and Cache.
Now you need to download the Motorola Defy 2.2 Boot Only SBF
Download the ZIP and extract the SBF from the archive.
You now need to flash this boot only SBF onto your Motorola Defy using RSD Lite.
Download RSD Lite
Connect the phone to your PC using the data cable and start RSD Lite. It should detect the phone.
In the file name dialog box, browse to the boot only SBF you downloaded and select it.
Click on Start and the phone should start flashing the SBF in the bootloader mode. Once it's done, your phone will restart and you will see the Finished status message and PASS in the result field.
Congratulations, you have now installed Android 2.2 Froyo on your Motorola Defy. In other words, you have upgraded your Motorola Defy to Android 2.2 Froyo.
Note: If you have any issues or doubts regarding the process, post on the official XDA thread.