To modify the Product Group/Kit Layout, Go to Themes > Your Active Theme
From the menu, Go to Pages > Product Details > HTML Editor
Here you will see the HTML for the Product Details page. The Product Group Layout is in a Visibilityarea called ProductGroupArea.
The Layout is divided into 3 main parts, the Table header, and the 2 alternating rows. Any changes made to one of these sections should also be reflected in the other 2 (such as adding a new column)
Example: Add a Column with a Link to the Kit product.
We'll add the new header the the Table Header section <th>Item Link</th>
Then we'll add the link to the 2 row sections <td><a href="/how-to-modify-the-product-group/kit-layout/table.aspx">How to Modify the Product Group/Kit Layout/Table.</a></td>
Example: Add the item thumbnails to the table for the child products
And here is the HTML
First we add an emtpy table header to make the table render properly <th></th>
Then we add the html for the thumbnail <td><a href="/how-to-modify-the-product-group/kit-layout/table.aspx"><img src="/resize?po=%2fstore%2fimages%2fno-image.png&bw=50&lr=t"></a></td>
As in the previous example we will add this to both rows.
First the link points its href to /how-to-modify-the-product-group/kit-layout/table.aspx, this will dynamically render the url for each product.
The /resize url takes several paramerts. We will be giving the parameters path (image path), bw (bound width), and lr (lock ratio)