If you are looking to remove or delete the notes added to a vendor submission while reviewing, you can do so under the Submissions section of the project. To edit notes made to a document from a vendor's submission, first click on the document with the notes. 

Once you've clicked on the specific document from a vendor's submission, you will then have the option to click Notes in the top left corner and show the notes made. From there you can click Delete under the note you want to get rid of.