How far can i edit a website (not my own)

how far can I edit a website (not my own)
To make it a better way for me to see it?

example: this website: http://ift.tt/2gqqrww
but I only have interest on the ranking. is there a way that I go on the source code (chrome f12) and make a window only with the ranking? (I will be refreshing this window constantly)