Share in a library
When you choose to publish a loop in one of the libraries you have access to, a copy will be made of the loop. Later on, if you want to update your published loop you just publish it again to the same library and your published loop will be updated with the changes you have made. When you want to publish your loop, you go to your loop under My loops, choose edit mode of the loop and click the name of the loop. At the bottom of the Start panel you will see Publish to library. Click that button and then choose in which library you want to publish your loop. If the loop is to be updated you will see a message about it already being published and that it will now be updated.