How to Edit Video Frames

I was thinking about bacon the other day and how there's nothing like bacon to add flavor to life, and that made me think of the Bible verse "you are the salt of the earth." So I wanted to make a video to illustrate the point. I happened to have a short video of a robin in our front yard pulling up and slurping a worm from the ground, and I thought to change the worm into a piece of bacon, then have the whole world turn bright colors when the robin was done eating the bacon. You know, like it happens in real life.
But how to edit the video frame by frame? 
It took me a day to find all the right (mostly free) software to do so after installing a trial version of Photoshop Premiere Elements and discovering that the free version leaves a giant black watermark on your video so you can't actually use it. 
I've embedded the final video for you to see my handiwork. Given that it's my first try at editing a video frame by frame and then adding audio, I think it's a pretty good product. 
I'm betting you can do even better. But save yourself a lot of time and money by reading my instructions first.

Record a video on your digital camera and download the file to your computer.

Download a free copy of VirtualDub. This is a very simple software that will save each frame of your video as an individual image file. Open your video in VirtualDub by selecting "open video file" from the File drop down menu.
To split the video into frames, select "export" and then "image sequence" under the File drop down menu. The name you give the first file will be given to all of the files with a sequential number extension.
I saved my images as .jpg but you can select other file formats.

Open the frames you want to edit in any photo editing software such as Photoshop or Corel Photopaint. Edit as you would any other image: fix the color, change to black and white, add objects, etc. This is where your work really starts. For the one minute video I edited here, there were almost 700 frames, and it took ten hours to edit half of those frames. If you are editing with the level of detail that I have in my video, it is very helpful to have a pen tablet, but you can use a mouse if your hand is steady.
Keep several frames open at the same time while editing so you can refer back to previous frames and ensure continuity. If you are adding an object in motion such as my strip of bacon, remember that there is very little change from frame to frame. Save the video frames without changing the names assigned by VirtualDub because these must remain sequential. If you delete even one frame, the video will no longer load.
It is a good idea to save and run your video after twenty or forty frames so you can see your progress and fix any mistakes before you proceed to the next batch of frames.

Open the image sequence in VirtualDub again. To do this, choose "open video file" from the file menu, then click on the first file in the sequence (mine was "bacon0000.jpg"). VirtualDub will open all the images in the sequence automatically. Re-save the image sequence as a video by choosing "save as AVI" from the file menu.

Open the video in Windows Movie Maker if you want to add audio. Import the video file that you just saved. Import any audio files you would like to add. Drag the video file to the video timeline at the bottom of the screen. Drag the audio files to the audio timeline below the video timeline. Play the video so you can see where to drag the audio file to.
Save the project and publish it when you are finished.