Step 1 Press Insert + F6 to get a list of header tags on the page.

Step 2 Select the h2 tag with a name n Comments :2. n refers to the number of comments on the page. For example, if there are 4 comments on the page, select the h2 tag with a name 4 Comments :2. Then press Enter to get the focus on the Comments header. If you don't find a header matching to the above pattern, there will be no comments.

Step 3 Press Tab to navigate among the authors of the comments. 

Step 4 Once you landed on the comment that you need to delete, press Down Arrow until JAWS says Link Delete.

Step 5 Then press Enter to access the prompt that confirms to delete the comment. Press Enter to confirm the deletion. Otherwise hit Tab to hear Cancel and then hit Enter.