How do I completely remove an image from my .blend file? I'm creating a model for a 3D game that will eventually be exported using a custom Python script. This model makes heavy use of UV textures.

However, the project now references a bunch of images that are not used by any objects in the project. Example:



I don't want the first two, or the red_bubble.png image. However, I have no idea how to remove them from the project. Selecting one of them reveals that there are "2 users of the data" although I am not using it anywhere.

How can I get rid of these excess images?
If you have an image (or other piece of data, such as a material) you can force remove all users by Shift clicking on the X next to it's name. This will "mark" the data for removal upon closing the file. 

After you force remove the data, you'll need to reopen the file in order for the data to be removed. You can do this quickly by saving the file with CtrlS and then opening it with CtrlShiftO and selecting the file.