You need to scroll down the page to the "Can I report a breach online?" section and then click on right click on the link and select 'Save Link As' or 'Save Target as' to download the form entitled "Personal data breach reporting form" before you begin to edit it. It can then be returned to the ICO at the address shown on the form.
If anyone has trouble accessing the form, just ask me and I will send you a copy!
I'm busy working on my blog posts. Watch this space!