4 Westlife Tickets Odyssey for 30 May 2012 Swap for 4 Tickets 20 June 2012 in Odyssey ?

I have 4 Westlife Tickets for Odyssey 30/05/2012, West Upper Tier, Row Y would like to Swap for same venue concert on 20 June 2012. Received these as a present but I have a holiday booked for this date.