Trunk lid

The wife's '98 Malibu had a wing/spoiler on the trunk lid when she bought it used a few years back. Looks good but it adds extra weight to the lid and it won't always stay open. Usually, it will wait until you're leaning inside the trunk, then it comes down and hits me in the head or back. Looking for a cheap solution to this problem (without removing the wing). Any way to adjust/change the spring to keep the trunk lid open? I thought about cutting off a piece of broom handle but......(haha)