The easiest way is to uninstall the apps that are putting those ads in your notification and either install a paid (adfree) version of it or install a different one that perform the same function.
Next up, you can try luckypatcher. It is able to patch apps and make the code that displays the ads nonfunctional. But it isnt a perfect science, so it may actually patch the app incorrectly and make it not work at all.
You can also just delete the app(s) that is pushing those ads. I honestly haven't seen a single app that pushes ads to the notification bar that is worth a crap. It seems that only the halfassed/poorly written/poorly supported/useless apps are the ones littered with the notification ads.