This method roots a rooted Android 3.0 (gingerbread) firmware of SE Xperia Play. Just follow these instructions to root the Xperia.
1) First you need to unlock the bootloader of Play. Go to the link given at the bottom to unlock it the official way.
2) Then download modded image file from the link given below.
3) Set up ADB on your Windows by following our guide.
On your computer launch the “Command Prompt” or the “Terminal” incase of Mac OSX or Linux.
4) Then, copy the img file downloaded in the previous step (play_modded.img) to the "fastboot" directory in the ADB setup directory.
5) Then run the following command:
Windows (in cmd prompt):
fastboot flash system play_modded.img
Linux (in terminal):
fastboot -i 0x0fce flash system play_modded.img
Mac (in terminal):
fastboot-mac -i 0x0fce flash system play_modded.img
6) Wait for few seconds for the process to complete.
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