The procedure is slightly different if the impact gun doesn't spin nut off because the long bolt is turning. In that case, you have to remove the hockey puck to gain access to the head of the long bolt and hold it. That hockey puck can get siezed from being installed for a long period of time making it hard to get a hold of and pull out. One method that has worked well for me removing the puck is a rubber tipped air nozzle. Again, clean the area real well where puck is installed. Be very careful doing this. Wear heavy leather gloves, and I placed a heavy cloth over work area with free hand to control ejection of puck. Remove the grease fitting in puck, place rubber tip of air nozzle in grease hole, and give it a shot of air. This will usually eject the puck from the coupler. Again, be careful. Manage the ejection of the puck or it can become a projectile when it comes out of there.
Find an appropriate size drift shaft that properly fits the inside of the hole in the loader arm socket to knock out tapered pivot pin.
Your going to have to give that drift shaft a good whack with a sledge to unseat the tapered pin from its socket. Once unseated, it will eject out the hole in in the back of the coupler.
You now have the coupler disconnect from loader arms and can pull it free of machine and perform repairs. I'll probably replace pivot bushings while I've got it off and replace pins if necessary. The other repairs I have to address on this unit is the left tilt cylinder attachment. Seems the user allowed the retainer bolt for the left cylinder attachment pin to fall out, which allowed pin to work its way out resulting in pin movement and wallowing of pin boss of coupler, buggered up the pin boss pretty good.
Also did a little damage to the bushing in the tilt cylinder rod eye. I don't think it's damaged the rod eye just yet.