if you have root access, login to your whm root and in the left sidebar find : "Copy an account from another server with account password"
If it is a big account copying it and restoring via whm might fail and is not recommended normally. If you have root access use /scripts/pkgacct username to generate the account backup and scp it to the remote server and restore it using /scripts/restorepkg username . For multiple accounts, this can be automated by using a script