Can i backup only _sync:user docs?

I need to remove all docs from a bucket but i would like to save all my user to restore them in a new once. I can manage design_docs to backup views but i don’t undertand how to do the same with the users.

I used this command to backup:

/opt/couchbase/bin/cbbackup test/ -u Administrator -p password -b mybucket0 -k '_sync:user*'

And this to restore:

/opt/couchbase/bin/cbrestore test/ --bucket-source=mybucket0 --bucket-destination=mybucket1

Is this the correct way?

On file backuped i see:

"sequence":131980 and "rolesSince":{"tecnici":131978}

Can i reset them?

Attempting to back up and restore just the _sync:user docs isn’t recommended. Sync Gateway user documents include sequence information - migrating these documents without the rest of the bucket contents will result in unpredictable behaviour.

Thanks @adamf

So, how i can restore an user with the same password?

i have already sent to 87 users their password to test our application, and they used it for 2 weeks.