Their best bet probably is to get there as early as possible and just wander around hoping to run into one of the guys or their road crew as they're arriving to the venue or leaving it to do whatever it is they do during their downtime between set up and soundcheck and showtime. It's still a bit of a longshot, but it does happen. I've seen the band coming and going while standing in line as well as members of their crew. Hell, one year Mige handed out Halloween candy to everyone in line. I feel like calling the venue would only get them fed a polite line about how they're not allowed to do that. Other than having a contact with someone associated with the band that can help you out, I don't think there's an easy or guaranteed way to make sure anything someone wants to give to the band gets to them.
On the other hand though, if your friend is desperate and willing to engage in an awkward moment, there's almost a 100% chance of running into someone from CKY at the show if someone is looking for them. They make themselves pretty available. He could ask one of them to pass it along. I don't think any of them would be willing to give it to Ville personally because that would be weird, but to the one of the crew that could pass it along might be a possibility.