Steps to insert a symbol:

1. Place cursor in the location that you would like symbol placed.
2. Select the 'Insert' option from the menu bar at the top of the editor window. A drop-down menu will appear.
3. Select 'SYMBOL' to open 'INSERT SYMBOL' dialog window (above image)
4. Select circle to the left of the required icon.
5. Select 'OK' to apply changes.