Write the 32 teams into a word document.
Print off the word document.
Take a pair of scissors to the printed word document (make sure you've printed it first or you'll damage your monitor)
Put the 32 names into a container or a hat.
Ask the people in your sweepstake to pick one out once they've paid.
The key to it is for you or the people who pick a team, to remember who got what team.
You may want to decide on the prize money beforehand to save any embarrassment later.
Once the World Cup final is played, have a look at the sports news on any well known news publication to find out who won it.
Find out who picked that team out of the container or hat and give them the prize money.