We are going to talk about replacing images you want. Alot of times, you don't want to ADD other images, just replace them with your own. This tutorial will show you how. All you need is an image editor like Photoshop to prepare your images.
Step1. Open up your Flash Library (Ctrl+L). Navigate through your Flash library to see the image you wish to change by viewing the preview window.
Step2. With the image selected, right click and choose "properties"
Step3. Pay very careful attention to the pixel size of the current image in figure (A) This is the time to
create your own image in Photoshop or any other image editor using the SAME pixel dimensions
Note: If you do not use the same dimensions, you images may appear stretched and distorted.

Once you have created your new image, press the "Import" button to navigate to it. That's it, you have just changed images easily without dealing with sometimes complicated timelines.