1) Login your Joomla administration page and from Extensions menu on the top select Install/Uninstall

2) Click on Browse button to select Availability Booking Calendar component ZIP file - com_abcalendar.zip

3) Once com_abcalendar.zip file is selected click on Upload File & Install button

4) Upon successful installation you will see this confirmation message

5) Click on Browse button again to select Availability Booking Calendar module ZIP file - mod_abcalendar.zip

6) Once mod_abcalendar.zip file is selected click on Upload File & Install button

7) Upon successful installation you will see this confirmation message

8) Under Components menu you will now have access to ABCalendar administration page

9) see how administration page works here