Here you go - like NM said you can also right click them and save them if you wish to do that. The logo is a transparent background so you'll want to have some color behind it if you choose to use it somewhere (notice you can't see the white below). Try to embed the forum URL link on things where you're using the forum logo or banner. An example would be including the forum URL in a YouTube video description.
Also it should go without saying, but please use good judgement on where and what you're adding the files to.