According to AP the pins are knock in pins therefore unless the design has changed from that in the drawing then there would not be a need for an impact wrench.
In saying that at less than 20,000 miles in a 2001 Turbo Impreza with a similar knock out pin design caliper, the pins took around 40 minutes to get out as the diameter had grown with hardish crud and it took a further 10 minutes of filing the pins to get them back to their original size. The design was changed shortly after that.
This design appears from an everyday maintenance point of view rather than a braking efficiency point of view well past their sell by date.
