not sure how the wrist pin is held in place,but there are the following ways.
1. pressed in will need special fixture to press it out without deforming piston[fox engines ise this method]
2.just slide it out but watch the teflon or brass pads on the ends[veco,webra,os and others use this on some engines.
3.remove the wire circlips that hold the wrist pin recessed in the piston.these clips are in a groove inside the wrist pin bore of the piston.