thanks for the heads up cvp, Actually I figured out what I needed.
step 1) in the projects window, right click the files folder and choose import, then import the images you want to load from a folder.
step 2) Add events at the start of your game to load from URL into your sprites, but instead of URL's, just add the images names such as "imageOne.png"
step 3) Export the game as node-web-kit
step 4) Go into the win32 folder that node-webkit created and find the file called package.nw and rename it to add .zip to the end of it. (becuase its really a .zip file)
step 5) open the zip file you just created by rename it to .zip and replace the images you had "imported" with new images.
step 6) rename the file again to get rid of .zip.
The next time the game is run it will display the new images.
cheers,
Mike