How to Remove Forehead Scar Tissue Under Skin Without Creating Additional Scars?

About 5 years ago, I fell & broke my nose. My glasses slid up into my forehead, creating two furrow marks vertically on the tops of my eyebrows. After stitches were removed and healed, there is still one vertical bump (perhaps scar tissue underneath) that makes me look like I'm always scowling with my brows. Would getting surgery to remove the scar tissue underneath, actually result in even more scar tissue and/or scars? How can I completely get rid of these without adding more scar tissue or damage to what's already been done?