Make your way to 33 Avenue de la Bourdonnais, where you'll meet your day's host in front of the strip of souvenir shops. Be sure to arrive 15 minutes before your tour's timed entry start; you'll know your guide by their outfit: a white shirt and a black jacket featuring the Viator logo. They'll hand over your coveted skip-the-line admission ticket, and you'll take the short walk over to the tower itself with your small group of just 15 people. This smaller group size ensures you'll have personal attention from your guide and that your tour retains an intimate atmosphere.
There's a special entrance for those with skip-the-line and priority access tickets; you may still have a short wait, but it's nothing compared to the hours-long queue at the standard entrance. Follow your guide to the interior elevator; they'll give you a quick orientation and escort you to the second floor. Take the next two hours to explore the first and second floors at your leisure, then rendezvous with your host to pick up your ticket to the Louvre.
When you use your ticket is up to you; you'll have the same priority access that you had at the Eiffel Tower, skipping the often long entrance lines.