How to edit contents of a drop down list using name manager?

I have already shown creating a drop down list using data validation in  the previous post.
How to create a drop down list using data validation?
In this post I will discuss how to edit contents of drop down list.
As I had said before, we identify data ranges that are used to create a list by a specific name.
In the previous post I had provided two specific names for the data i.e COURSE and COMBINATION.

There were 3 entries under COURSE and 7 entries under COMBINATION.

Suppose you want to edit contents of each list then follow the below mentioned steps.

1. Enter the extra entries into the respective columns in the REFERENCE sheet.

2. Select Name Manager under the Formulas Tab.

3. You can see two names listed in the dialog box i.e COURSE and COMBINATION

4. Click on COMBINATION. The range referenced by this name will be automatically highlighted.

5. Click in the refers to text box and then change the value of $C$8 to $C$10. The two entries 

    "MECHANICAL" and "ELECTRICAL" will be included in the COMBINATION list. 

6. Select OK.

7. Follow the same steps for COURSE.