Here is what you have to do:
Those wanting a day ticket for Sonisphere must put in an application for tickets by 23rd May, you can enter for any day you want to increase your chances. The people who will get the tickets will be notified by 25th May and can proceed to by tickets from there!
Day tickets will cost £80 plus booking fee.
Go here to apply: https://kililive.wufoo.com/forms/sonisphere-day-ticket-power-ballot/