Layout Modification Impossible

I want to modify the Texture layout from Site assist professional 1.0.7. I am using DW cs4. I do not want to use css scuptor for this modification (unless I have to). I only want to make the modifications to the graphics and import it back through the preset manager.

Here's what works:
I go through Insert > WebAssist > Preset Manager > Product: SiteAssist Professional Layouts > Export

If I export the Texture layout to my desktop (saving it as whatever file name I want) and then immediately importing it back without changing anything...it works.

However, if I unzip the file and then re-zip it back up and try to import it...I get "the file you selected is not a valid "siteassist layout".

How do I make changes (only to graphics files) after exporting and safely import a zipped file back into the layout manager? I just want to be able to customize the texture/slate layout for a site I'm working on. I also want to know how to do this for future reference. One would think this is a simple, straightforward process. Any and all assistance is appreciated (and needed).
Thanks,
Matt

I think the problem you are experiencing with directly editing the layout like this is rezipping it. I have just tried to do what you would like to without issue, here are the steps I took.

First export the layout, this should create a zip for you. Now open this archive and extract the folder that contains the images or other resources you would like to edit.

You can then directly edit the images from this extracted folder. Once you are done making the edits open up the zip for the layout again and delete the folder you were just working from, then drag back in it's place the folder you had extracted earlier. You can then import the zip file directly.

When I did it like this I was able to replace the folders directly inside of the zip with my updated images being used. When I created a new site from this layout it utilized the images that I updated inside the folders.

You are the man! Amen! I've been trying to figure that out forever. Thank you very much.
-Matt

You are very welcome Matt, it is always very satisfying to know that I helped someone accomplish their goal.