Pathfinder Weapon Finesse

Hi, all I was wondering how to implement this Feat in a Ninja class. I am able to add the feat no problem but it doesn't adjust the calculation.

Any help would be appreciated.

There's very little automatic allocation of game mechanics when you add a feat to a PC. Make the changes manually in the PC actions tab to the appropriate weapons - click the magnifying glass icon on the right side of the weapon entry on the actions tab and change the attack stat to Dex.