Changing the Symbology for all values at once

Problem: You have a shapefile with a large amount of values and you want to change the size or outline color of all the values. If your values are more than 5, this can be very time consuming to click each individual value and change the size or outline color.

Solution: 

1. Double click on the .shp to open the layer properties.
2. Navigate to the symbology tab.
3. Select all the values you want to change and right click.
4. select Properties for All Symbols.