You can get the manual on CD for 10 pounds UK from this source
http://cgi.ebay.com.au/Triumph-Tiger...QQcmdZViewItem
The manual covers Tigers up to 2005, but most of it still applies to '06 models.
You do need to remove the tank to get at the Air box, but it's not very difficult.
Search this site for info on air box mods.
Good luck.