Sony Ericsson XPERIA Arc [TUT]how to get rooted 2.3.3 with locked bootloader

First of all thanks to kokbiel for discovering this!

Do not try this if you have an unlocked bootloader or if you dont know what your doing! I'm not resposible if you break or brick your phone!

If you're allready on a rooted .181 or .184 and OTA update is available for you just update your firmware. If there is no OTA update available for your customazation version follow these instuctions:
- flash back to 3.0.A.2.181 generic with the flashtool
- Use Gingerbreak or Superoneclick to root your device
- Update your Arc using a OTA(over the air) update(Go to settings->About phone->Software update)
- Enjoy your rooted 2.3.3!!!

Update 1: it seems that the OTA update is not working if you did any modifications to/deleted system files so it's adviced to always flash the .181 firmware provided in this post
Update 2: if you have any battery problems after flashing the .181 firmware(if it's only showing 1%) removing the battery for a few minutes should solve this
Update 3: thanks to ricstc we now have a video tutorial on how to follow these instructions

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