You can remove releases from the Your Music page of your Record Union dashboard.
Click the 3 dots next to the release you would like to remove and select 'Take-down'.
This will remove the release from all stores and cancel it's subscription.
Note: Take downs are irreversible. After you have removed the release from our website, it usually takes 3-5 business days before the music gets removed on the stores. It's not possible to remove certain tracks on an already published release.