Changing a product's category

I've got about 400 products in my store. The database of products was passed on to me by another Zen-Cart store's owner who sells all our products as well. But the categories all the products are in are (for my purposes) incorrect.

I'm needing to create new categories and move all the products into these new categories. But when I go into a product's details page, there's no drop-down box to allow the main category to be changed.

How can I change the main category of a product? They're pretty much in a mess all over the place...

Back up one level to the category that a product you want to move is in. Then look for the little "m" button on the right. "m" in this context stands for "move".

Awesome :) Thanks!