There isn't much info available, other than word of mouth! I requested it for my in-laws' 40th anniversary & the cast member didn't even know what I was talking about!!!!
After we ate, the manager came to the table w/ a few servers & asked them to stand up. She then made an announcement that it was their anniversary & since none of us at been with them at their original wedding, they were getting re-hitched "Garden Grill style." She asked them a question (don't remember the exact wording) & then made them kiss while everyone counted to 100 (1-10, then 20, 30, 40, etc). I'm pretty sure they were also presented with a certificate.
It was very cute & my daughter, 5, thought it was hysterical to see Grandmom & PopPop on display. There was no charge. Hope this can help your friend!