I'm using QGIS 2.18. The screenshot below shows the print composer.
At the moment, the only way I can reduce the size of symbols in the print composer is to reduce the size of the symbol on the map.
In the attached, the green star symbol in the print composer legend is huge. How can I reduce the size of the green star symbol in the print composer legend, but keep the size of the green star the same on the map?