If you have so many steps and want to add your own comment in query steps in Power Query then go through this tutorial till last steps. Commenting in your query will help you to understand your query easily as well as it will become picky to other users.
Previously In Power Query: How to Extract Length Of the Text Using Power Query
Now directly jump to the detailed steps:
STEP1. I want to edit an existing query to modify it new version. So for this follow:
Go to Data > Queries & Connections
Now for open up the power query editor, double click on your Query.
STEP2. So here I want to edit one comment to one of my existing steps.
For this right-click on that which you need to add a comment to, in my case “Filtered Rows” and go to properties
STEP3. In this step, We will add Comment to that particular step;
For that, Go to properties > add a comment (In My case ” Extract Same to Characters”) in the description.
It has saved your comment in the power query now if you want you can follow these steps for your other queries as well.
Here you can see the comment by hovering to the particular query;