How do I report someone soliciting me to buy them to boost me?

I just had this happen, I added a guy because I was trying to put together some other silvers to get the hell out of ELO hell and he sends me a message and link saying I should buy a him for a boost. How do I go about sending Riot his information?

Personal: If you can't make it to the ELO on your own merit and hard work you don't deserve it. Go find another good player stuck in hell and go kick the gate open. Cheating is cheating.