Here's How to get the trackpad to work with full functionality, including the scrolling section of the pad and double tap click's, Gestures etc,

1. ApplePS2 (Download Here)

2. Install the Kext's ApplePS2Controller.kext and AppleACPIPS2Nub.kext using OSx Tools or Kext Helper, Alternatively they can be loaded in /Extra/Extensions.

3. Synaptics Trackpad.prefPane needs to be installed (double click prefPane; it will get installed in System Preferences under "Other")

4. com.meklort.ps2.helper.plist needs to be placed in /Library/LaunchAgents to save your Trackpad settings after reboot.

5. Under System Preferences Launch up the TrackPad panel and then customize your trackpad preferences to your liking

Regards
Callum