The “Multi Product Update” feature lets you change the information in multiple products at once if that information is the same across those products.
Navigate to the Multi Product Update tool under the Actions drop down at the top of your Product list.
To update a field across multiple products, find the desired field and click on the Export button by hovering over the top right corner of the field (See image below)
In the pop up window (see image below), confirm the information is correct or edit further then click Next
Select Copy to other products.
Select the products you would like to copy the information to, you can select all products at the top if applicable. When you have selected all products you want to copy to, click on the Update and Continue button. (see image below)