Came here Monday, June 27th in the evening. Purchased a "VIP Ride Package for 2" Groupon a few months back that included free admission to the Voodoo Nightclub and a "BOGO Half Off (beer or well drinks)" voucher.
We walked through the casino floor, located the zipline kiosk and was directed to go up a flight of stairs to a storefront to purchase/redeem Groupon, show ID, sign waiver and get hand stamped. After that process we were then told to head towards the Voodoo Club entrance and take the elevator to the 51st floor (there are signs and placards along the way directing you to find the zipline area).
You'll go to the outdoor area of the club (views there are amazing, you get a near 360° view of Vegas!) and down a few flight of stairs to the zipline booth. Be asked to show your stamped hand and offered a Go-Pro recording of your zipline ride on a microSD card for $16 (we did it and it came out good, just not HD quality looking).
No hats, cellphones or anything loose goes with you during the ride. You're provided a small locker to store your belongings steps. An attendant holds onto the padlock key until you're done.
The ride itself was a bit underwhelming to say the least, it's just a faster moving ski lift with a lap belt in my opinion, you descend towards another building then back up again to where you started. The views from the zipline is amazing but it goes by too fast to really enjoy it.
After the ride you receive your microSD Card if you chose to purchase it earlier and you'll be given the option to buy photo stills at the booth (we opted out because we already got the video recording so why bother?).
Whole experience was OK, at least now it's off the Vegas bucket list.