Need help replacing image within a layer

[klaurelw]

I am working in CS on a document with layers. The layer I'm working on has a photo placed within a box with rounded corners. The image box has the following effects:outer glow and stroke. I need to replace the existing image with a different image, and I can't seem to get it to work right. The existing image is also missing from my images folder so I don't have the source. Do I have to start over and make a new layer?? Please help!! Thank you!!