Drink this beer, and enter another competition when you have enough beers.
When you enter a contest, you want to be entering the beer in the best state possible.
There's really no easy way to move beer from one bottle to another that wouldn't perhaps risk oxydation.
There will be other contests, and other beers to enter. And if you want to enter this recipe, then brew it again in time for the next contest.
And in the future, for every batch you bottle, bottle at least a sixer in plain, unmarked 12 ouncers, and set it aside, JUST for contests. that way come contest time you will have bottles that you can enter, without having to worry about stuff like this.
We get threads like this all the time, and I don't get why folks would even consider messing with something like this....The point of a contest is to enter your beer in it's best condition possible. Not to do something that could oxydize or infect your beer, just in the hopes that it will turn out "ok."
The point of entering contests is to be judged by experts and experts can and will pick up any flaws in your beer.
So really, you don't want to do something that could render your beer in less than stellar or pristine conditions.
There are a million contests, and most of them are on an annual basis...this won't be the only contest, nor will it be the only batch of beer you make...
It's funny. this is the only hobby I have come across where people would try something like this before submitting their heart and soul to a panel of judges.......I mean you don't hear a painter say, "I want to enter my canvas in a contest, the rules say it can be no bigger than 8 x 10, mine's 9 x 12, so I guess I need to get out an exacto blade and cut my painting down to size." Or in your case, I need to paintings, and I have only one, so I'm just gonna cut it in half.
Talk about cutting corners.
If it ain't gonna be perfect, then don't bother......Don't try to compromise...you would be surprised at what the judges can pick up on.
There will be plenty more in your brewing career.