It should be a easy fix provided you have'nt wallowed out the hole in the lift arm.
The pivot pin has a taper that mates with the one in the lift arm when the bolt pulls it to the outside.
Remove the grease nipples.
Take a punch and drive the pin with the broken bolt inward, if its still wedged in the taper and takes a few good raps with a 2lb hammer thats a good sign.
Push the pin fully into the bobtach to disenguage the lift arm.
Losen the bolt on the other pin 2 turns and rap the head of it to losen that pin too. Buy a extra long to reinstall the new pins as the correct one does not reach in far enough to hook the pin and pull it most of the way out. Then use the correct length bolt to seat the pin
There are bushings in the bobtach you can change if needed. Besure to torque the new bolt to 115 ft lbs and keep checking it for awhile as they do like to come lose. I also like to ship the side to side slop out with a flat washer or two while I have this apart. Saves bushing and pin wear and keeps the dirt out.
If the lift arm is worn there is a taperd reemer available to repair the taper or worse case you need to weld in a new one.
This is a fairly common problem, that usually a new bolt solves. I make a point of cheaking mine every time I grease.
Also there was a update to the pins several years back. my 93 had the old style where the pin was threaded in the tapered end. I had the tapered portion break off the pin. The new style the bolt passes completely through the pin to the inside end. If your bolts are 4 to 5" long you have the new style. There are likely factory installed now for several years.
Ken