In order to customize a Web Photo Gallery template, you’ll have to open the HTML pages and make the changes there. If you’ve never worked with any Web authoring tools, I’ll get my warning out of the way right now and tell you to be careful! The best plan is to find and copy the folder that contains the Web style you want to customize.
You’ll find the Web templates in Hard Drive: Applications:Photoshop CS2:Presets:Web Photo Gallery on a Mac or C:\Program Files\ Adobe\Adobe Photoshop CS2\Presets\Web Photo Gallery on a PC.
Duplicate the entire folder within the same Presets folder location so that your copy will appear in the Web Photo Gallery dialog.
To make changes to the template, you’ll need to use a Web authoring ...