Here is a way to do it if you are a beginner with minimum tools. Keep the wheels attached to the frame and fork so you can get leverage without the frame jumping all around. Stand on the other side of the bike from the side of the bottom bracket that you are removing. Lean over the bike and hold it down with your stomach (there are advantages to being slightly rotund). Hold (pull toward you hard actually) the bottom bracket tool with your left hand as this will keep it from popping out away from you. Set the wrench so that you are pulling up with the right hand in the proper rotational direction. The longer the wrench (I use a 250 ft/lb beam style tork wrench about 2 1/2 feet long), the more control you will have over the pull.
Right hand up.....Left hand toward you.....Body weight down. This is how to herd bottom bracket cats.
Pushing down toward the floor with any wrench is a disaster waiting to happen because the most stubbron fastiners like to come loose at once.
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