Users have a few options when it comes to changing the order of values along a bar chart.  

Let's start with this bar chart:

Option 1 -- order by values

1. Right click on the visualization and go to Properties

2. Go to the Appearance menu and select the checkbox that says Sort bars by value, which will result in this bar chart

Option 2 -- 

1. Go to the Edit menu, Column properties

2. Select the column that is on the x axis of your visualization

3. Go to the Sort order tab

4. Set radio button to Custom sort order

5. Click the configure button and manually configure the stort order

6.  You may also choose one of the other radio button options