What you need:
- An install of 10.4.7 Tiger or download and extract the 10.4.9 combo update which can be found here .
NOTE***: Use pacifist extract the combo.
Open a new Finder window and navigate to your Tiger install or combo update.
Navigate to and copy these files from your tiger files to the corresponding location on your leopard install.
If you can't find the location on your leopard install simply use Go:Go to Folder command from the Finder Menu and enter the directory to go to. (ex. /System/Library/PreferencePanes)
Click the Apple in the top left hand corner of the screen. Select System Preferences from the dropdown menu. Select Keyboard&Mouse to open their settings. Once open select Trackpad from the tabs above. Check the box next to "Place two fingers on trackpad and click button for secondary click".
You may now close the System Preferences and reboot. When computer restarts you should be able to right click!