You can change the configuration of multiple users at once in BioStar 2 with the batch edit feature.
Below is a sample scenario where all user periods (valid user account dates) are changed at once.
1. Click down arrow button and click select all to select all users on the User menu.
2. Click Batch Edit.
3. Change the user Period accordingly and click Ok.
To manually sync the device again, take the steps below
1. Select All in the device menu:
2. Click ... and then Delete Data & Sync Device
This will force sync the device. If you have many users, it may take some time for this procedure to finish.