Yup, like John E says, you only have to remove the levers and like Pete says, "just don't use them".

If you do remove them, simply remove the bolt that holds them on and remove the levers. Remember that the bolt also holds the primary lever, so you have to put it back in after removing the suicide levers.

You will also have to tighten the brake cables after you remove the suicide levers.

Personally, I do not think that the so-called suicide levers pose much of a threat. HOWEVER, I recently rebuilt an old bike for a friend of mine. I chose to remove the suicide levers because he weighs 260 lbs and has very strong legs. I thought it likely that he could generate enough inertia to overpower the leverage of the 'suicidee' brake levers, so I removed them.