If you have water leaking from the bottom, simply contact BUNN. They will send you a replacement seal kit and your Coffee Maker will leak no more. This is a common problem with 'most' BUNN coffee makers.

Your problem is caused by the pour-in tray leaking where it mounts to the tank. There should be 2 screws under the pour-in lid, and a third toward the rear of the brewer. if you take them out & lift up carefully, you can see the pour-in tray. in the bottom of the tray, there is a bolt that mounts the tray to the tank. If you remove that, you can lift the pour-in tray out. Be careful, as these trays get brittle over time, and are prone to cracking.