Once it opens it, you should be looking at a window containing a dozen or so weird-looking icons. Look for the one called "DITL" (as seen below). Double-click it to open it up.

This is the collection of all the resources
in your Filter Factory filter. The one we're
concerned with is "DITL."

Now you'll see a list of numbers in two columns, labeled "ID" and "Size." Double-click on the one with the ID of 16004, as seen below. (It should have a size of 532. This number will change by the time we're done.)

Select the resource that governs the filter's
appearance (16004).

Now that you've opened that up, you're looking at your filter's interface. It doesn't have all of your settings listed, but they're there. You should see a rectangular box, some sliders and a "Cancel" and "OK" button. From this point on, any changes you make to this window will be made to your actual filter.

The basic Filter Factory filter interface, as seen in ResEdit.

The first thing I did to my filter was to make its interface bigger. To accomplish this, just stretch the window. You'll notice that your interface elements don't change. To move them, just select them and drag them. (You can select all, move an individual item or drag a marquee around multiple items.)