This repair is best done with high density polyurethane bushings rather than with the soft (and partly cured) rubber bushings furnished originally by DADI.  If your bushings failed in less than perhaps 3000 hours,  likely part of the problem was misalignment of the generator and engine when they were assembled on the skid.  My unit was out of alignment about 2.5mm (measured top of flywheel vs bottom offset).  This caused "scrubbing"  on the bushings with each revolution of the flywheel which wore out the old bushings prematurely.

Generator disconnect:
1) Disconnect electrical connections from generator control box.
2) Loosen the four bolts holding the generator down.
3a)  It will help if you have a couple of pieces of 4" wide  x 0.10 inch x about 18" steel cut to lay across the skid under and behind the generator.  Then as you slide the generator back from the engine,  it will have something solid to lay on.
3b) Slide the generator back out of the coupling revealing the six coupling pins.  It may be that all of the rubber has disappeared off these pins.
4) Remove the six pins from the generator flange.  Loosen the nut and leave the nut about flush with the end of the bolt.  Tap GENTLY on the nut so as to dislodge the tapered pin.  It will not hurt to put some rocking or tapping force on the pin as you tap on the nut.  Use great care not to damage the threads on the tapered bolts.
5) Once you have removed the tapered bolts,  inspect them and file or grind any grossly rough spots smooth.

Reassembly of the bushings to the generator coupling plate.
6) Apply a small amount of lubricant (chassis lubricant or similar) to the bolt body and to the inside of one of the new Urethane bushings and slide it onto the tapered bolt.  (The washer goes on between the new bushing and the coupling mounting flange.)
7)Repeat #6 for each of the other bushings.
8) Put a small bit of lubricant on the inside of each of the six bores in the flywheel.
9) Push the six urethane bushings into the flywheel holes until the bushings are FLUSH with the face of the bore hole.  The bushings are a close fit in the bore holes,  but slide in fairly easily.
10) Put the six washers on the six tapered bolts now sticking out of the flywheel.
11) Carefully slide the generator back toward the engine.  align the generator coupling wheel with the bolts and CAREFULLY move the generator into position while watching to make sure the the tapered bolts and bushings are not pushed into the flywheel.
12) When the bolts come through the coupling wheel,  install the nuts on the six bolts and tighten securely.  You can use a pry bar between various nuts and the coupling wheel flange to prevent the generator armature from turning while the bolts are being tightened.

Alignment of the generator and the engine.
     It is essential to have good alignment between the generator and the engine to prevent excessive wear on the bushings.
13) Get the generator and the engine flywheel into as good alignment as you can by eye.
14) Use a standard drill bit as a feeler gage and move the gage slowly around the entire 360 degrees of gap between the engine bell housing and the alternator drive flange which holds the bushings.   Make sure the gap is UNIFORM within a few thousandths of an inch all the way around the perimeter.  This is VERY IMPORTANT and it takes TIME to get it aligned both vertically and horizontally!
15) Use a suitable gage and measure the offset from the face of the flywheel to the back face of the generator coupling wheel.  (On my unit,  the offset is about 0.25 inch,  but this is not critical.  What is CRITICAL is that the face of the flywheel be as parallel with the face of the generator coupling wheel as possible.  A maximum runout of about 5/1000 inch is desirable,  0.010 absolute max.
16) recheck 14) and 15) several times until both the measurements are simultaneously OK.  It may well be that you will have to use some spacers under the generator (or the rear of the engine) to be able to obtain precise alignment.
17) Note:  When you tighten the four nuts holding the generator to the skid,  this MAY mess up the alignment.  Try to keep the nuts "fairly snug" all the time you are doing the final alignment to minimize this problem.

Since the alignment is so critical,  I welded " horizontal stops" at 4 locations in an effort to limit future movement while allowing the generator to be slipped out (away from the engine) for future repairs.  I used several standard washers to raise the front of my generator into alignment with the flywheel.  In my case,  these were placed along the outer edge of the generator mounting rail near the bolts.  Your generator will likely need slightly different treatment to bring it into alignment.