Well officially if you want to be confirmed on that 8am flight you would have to pay a $100 change fee plus any fare difference (if your ticketed fare is not available). Or, to do it for free, officially, you are supposed to go standby. Depending on the TA you get though they may just confirm you on the 8am. I would call and check the loads and if it looks good then go standby. If you are checking bags make sure to go to the ticket counter to check in and have them check your bag on the nonstop (which they will do no problem).