Its very easy
You can flash european version after flashing the phone goes in recovery mode to install the dbdata. If this was not possible flash the dbdata manually in PDA-Section. After flashing dbdata hold power an volume up to restart the tab. If the tab restarts let of the power button and hold the volume-up to go into manual installation mode. Now the Tab should install the dbdata manually and make an restart. Then it should boot normaly.
If you need dbdata for this tab i can send you a download-link
Note if you flash the european version flash only the OXAJK5 or XXJK5. This versions are the latest officially Samsung Versions. And as i know they have no signed bootloader. All newer versions had new signed bootloader so after flashing you can't downgrade anymore (i don't know if you can downgrade after ressurecting with RIFF again
)