Before you read any further let me clarify who this is for. This method is for those of you who accidently updated to .621. If this is you then you found out the hard way that there is no root method for .621. There is still not a root method for .621 this is just a way to get back to a rootable state being that there is no way to sbf to a previous droidx build. Some of you found out the hard way that if you try to sbf to a previous build then you will be bricked. This is because Motorola has built in checks like on newer moto devices that prohibit reverting to an older firmware. Just to be clear I will say it again there is still currently no root method for .621 so do not update to .621 if you wish to maintain root on a DroidX build.
Some very resourceful DroidXers over at Rootzwiki have discovered that although you can not flash any previous DroidX Sbf files once you have upgraded to .621 you can flash previous MilestoneX Sbf builds! You should be aware that doing this will effectively turn your phone into a MilestoneX which is the European version of the DroidX. From here you can root the phone, install bootstrap recovery, and flash a DroidX rom of your choice, once again making your phone a DroidX. If you need to from there you should be able to flash the .621 sbf to get back to stock. This is kind of a messy way to get your root back, but it is nice to know that there are options available to those of you stuck without root.
via RootzWiki
Last edited: