How to change series name in excel chart | Legend Entry Name in excel |Quick Tour chart series name

First question arises why do we need series or legend entry option ?
The answer is simple :when we want to represent multiple information
on the same graph then we need different colours to differentiate them. And in this Legend Entry option helps us. ​For example
I have the data of 7 students, marks they obtained
in 4 subjects, Hindi, English, Maths and Science
For this I created a column chart
X axis represent Rollno
​Y axis represent Marks
Blue colour represents Hindi subject marks obtained by each student
Orange for English
Grey for Maths
Yellow for Science

Now we want to edit these series name with
​correct information.
For this select all series by clicking once, ​a white box appears
then right click on it, click on select data option, a box appears
choose series1, click on edit on the left hand side, Edit series box appears
type name that u want, similarly choose series2 click on edit type name
Lastly click ok

[FarenHalven]

Is there a way to select the cells desired instead of typing them in manually? Thank, great vid!