Sebmit a second run of the same game?
It's better to resubmit a new run. It helps you keeping track of your progresses. (I know some runners DO edit their old runs, but do whatever you want)
as an added bit of info your info section on your profile tracks the total number of runs and the current personal best runs for each game you have put runs into, just so you are aware of it. so always be making new runs, the better ones will always show up over your old ones anyways. =)