uninstall 6.0 from your computer and reinstall the 5.0 OS you want to use on your phone. delete the vendor file, then run the loader.exe to begin the loading process. the loader will prompt you stating that the files you are about to load are older than the ones currently on the device. just select to proceed with the load and it should all go as any other OS upgrade.
the following is a little outdated and shows how to do it using DM and backing up your apps via JL_Cmdr or BBSAK. i think its unnecessary since the loader.exe does all of that for you.
