With MS Outlook it is really simple to sync your employee's Kickserv calendar.
Open Kickserv settings > manage users
Click on an employee's name
You will notice thier unique iCal link on that page
Copy the entire "webcal://kickservapp…" or click the share link at the right end of that link.
Send this entire link to your employee. If they open this email on the device that has Outlook installed and click the iCal link then Outlook will ask if you would like to install this calendar - done!