To uninstall you OS is simple.
on your computer, go to control panel -> add/remove programs -> remove blackberry.
download a new/old OS (i like using 5.0.0.415 because it still has the standby password locking top buttons)
install it.
go to C:/program files/common files/RIM/blackberry
delete the vendor.xml file.
plug in blackberry
run apploader
follow instructions to downgrade
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