It's not necessary to uninstall it. Simply click the arrow to the right of the red Adblock Plus button and choose "Disable on Photobucket".

If you really do want to uninstall it, click the Firefox button, go to Add-ons | Extensions and remove it in there.

I don't have this red button.....how can I find it? thnx

I have the same question. I don't even remember installing adblock plus, yet the word "block" is above videos I want to download. I used to be able to download videos with a program I don't remember the name of, but something is blocking it now. When I put my mouse over the word "block" a message says "click here to block with adblock plus." I don't want to block the videos I only want to download them.