Thanks for posting your questions here.
In order to prevent the "About Us" section from showing up in your future listings, you will need to update your Seller Details profile which contains those details, which can be done by mousing over the "Profiles" tab within your account, selecting the "Manage" option under "Seller Details" and then clicking the "Edit" button next to the profile in question.
From there, just click the “About Us” tab along the top of the Seller Details editor, delete all the text within that section and click the “Save” button at the bottom of the page. Once you have done so, any future listings you post with that Seller Details profile should not contain an “About Us” section.
If you are also looking to update the details that will appear in the similar “Shipping” section in your future listings, you will need to click the “Shipping” tab along the top of the Seller Details editor and make the desired changes there.
However, if you would like to modify any of your main Shipping profiles which are used to populate the fields within the Shipping Tools section of the lister page in bulk, you will need to mouse over the “Profiles” tab, select “Manage All” under “Profiles” and select the “Edit” option from the drop down menu next to any Shipping profiles you would like to edit.
On the other hand, if you are looking to change these details in listings that are already active, different processes would be required.
You may be able to use the “Bulk Relist” tool on your Active Listings page to make minor changes to the “Shipping” section within your descriptions, but the removal of the “About Us” section and any other changes you may need to make to the main shipping fields would likely need to be done through the “Revise your Item” form directly on the eBay website.
I hope this helps. If you need any more specific assistance making these changes, please feel free to contact our Customer Support team directly from under the “Help” tab within your account and we will be happy to continue working with you.