How do I align the blade in the center of the folder when installing it?

To put the blade in the center of the locking liner knife, make sure the pivot is snug to the washers. Then, tune the blade, so it has no wobble with the lock disengaged, but free enough to open and close .
Once this is achieved, loosen the screws that hold the bushings in place a small amount. Then, torque the liner with your hand in the forward or reverse direction to adjust the blade into the center of the liners. Tighten the screws to hold the liners in place, once you have it where it's correctly positioned. This should do it.