How do I download Idvd?

You can't; you need to install it from the computer's original disks(if it shipped with Mac OS X 10.6.8 or earlier, not including Mac OS X Server) or from an iLife DVD, which may be available at places such as Amazon or eBay.

(80776)

If you have to purchase an iLife disc in order to obtain the iDVD application be warned that the iLife 11 disc only provides themes from iDVD 5-7. The Software Update no longer installs the earlier themes when starting from the iLIfe 11 disk nor do any of the iDVD 7 updaters available from the Apple Downloads website contain them.

Currently the only sure fire way to get all themes is to start with the iLife 09 disc:

This shows the iDVD contents in the iLife 09 disc via Pacifist:

You then can upgrade from iDVD 7.0.3 to iDVD 7.1.2 via the updaters at the Apple Downloads webpage.

OT