Download either Tampermonkey for Chrome, or Greasemonkey for Firefox if you want to run this script repeatably:
Tampermonkey: https://chrome.google.com/webstore/detail/tampermonkey/dhdgffkkebhmkfjojejmpbldmpobfkfo
Greasemonkey: https://addons.mozilla.org/nl/firefox/addon/greasemonkey/