Ok here is a pic of a "spider gear " replacement kit.
Its not that bad , you will find curved washers in the kit , make sure you re install them on the back side of the gears , 2 of the gears are splined for your axles and the other 2 are not.
Make sure you clean out all the old parts from the carrier, use brake clean and try and make it hospital clean, any bad pieces left in there could cause big problems.
If the gears are broken , try and find out why , make sure the ring and pinion do not have any missing teeth that may have jammed up the rear causing breakage,
I cannot express how important it is to clean everything while apart.
The gears have to be timed so they are 180 degrees apart from each other or the retainer pin will not line up with the case, It might take a first timer a few tries but you can do it.
Lube everything very well with gear oil before reassembly.
PM me if you have any other questions...
Good Luck
Desert