Once you have converted a body into a box you will have a Content Box with just the original Body Tag in it
You are probably going to want to add some new blocks to the box. You do that by selecting the type of element you want to add from the pull down menu at the bod of the Edit Content Box section:
Once you have added the elements you want click the ok button to save the changes and take you back to your page
| Next: Ordering the Elements in the Box |