1) Click on 'Quote' on the post you wish to include in your reply.
2) A reply page will open up with the complete post of the person whos quote you wish to include.
3) Remove any portion of their post that you don't wish to include by left clicking at the end of the unneeded comment and dragging your mouse to the beginning of the unneeded comment to highlight it.
4) Once highlighted. clicking on 'BACKSPACE' will remove it. (be sure to not delete the two quote marks [q] [/q] )
5) Add your comment at the bottom and the 'quote' will appear within your post in a white window.