Start with whichever you prefer * Tools > Options > Add-ons * Ctrl+Shift + A * type about:addons into the location bar * Firefox glow button, second column > Add-ons Click on the Green Puzzle piece on the left side (mouse-over, or widening screen would show "Extensions") Choose "Uninstall" or "Disable". Many extensions also have an "Options" button the modify/customzie behavior.