Legendary Gear is in general a good thing to hold on to, especially if you want to use a different bonus at some point.
But if you really want to get rid of them, you can always sell them for gold in the Marketplace. Sometimes there are crafts in which you can use legends, so you can wait for those to appear. You can also split them to parts so that they won't take that much space in your inventory. If you have two identical Legends you can also boost them.
Legendary Gear is also used to Awake other items. Check our the video below to find out more: