In the Skype for Business software client, add the meeting video address into the Search field and hit the Enter key. This will show you a contact with the same meeting room name. Right click the Contact and chose either Video or Audio Call. You will then be joined into the video meeting room.
Note: Skype for Business users will need to have Open Federation set or add 'courts-video-link.service.justice.gov.uk' into their allowed Skype for Business domains list. If you are having issues, you should speak to your Systems Administrator.