The tutorial suggests using one frame as a guide to create the blurred area, once you have one frame imported you can move it, re-size it, and otherwise manipulate it using key-frames to keep it covering the relevant area of video.
You can export frame by frame if you need to though, although it's much more complicated and time consuming, editing each frame individually is called rotoscoping,
to export as one big file which you can edit in an image editor and then re-import to Premiere do this:
file> export> movie> settings> filetype> filmstrip
to export the frames as a series of images just choose the image type in the settings dialogue box above, you can use JPEG, GIF, TIFF etc.
Panasonic SD9, Panasonic NVGS-75, Canon MV600i