Should be fairly simple. I haven't done a D44 but I did replace the ones in my old D35. There are some differences but the procedure is similar. For the D44 it is more work to get the axle shafts out.
Please note that this will work only if you have an open differential. If you have a LSD there are clutch packs behind the side gears, and as far as I understand it requires more work and special tools to disassemble, and may require removal of the whole carrier. If it is an open differential you should be able to replace them with the carrier in the axle, using something along the lines of the following procedure:
-Chock the front wheels, lift the back end, secure it on jackstands. Do not just put it in Park or gear and engage the 4x4 to secure the front wheels. You will need to put the transmission or transfer case in neutral so you can rotate the differential carrier.
-Crack open the differential cover to let the fluid start draining.
-Remove the wheels and all brake components so you have access to the axle hubs.
-Using the access hole in the hub, remove the four nuts securing the axle retaining plate.
-Remove the axle shafts; you do not have to pull them all the way, just far enough to get the axles clear of the gears inside the carrier.
-Inside the differential, on the side of the carrier, there should be a hex bolt securing the cross shaft. Remove the bolt, then slide the shaft out.
-Rotate the side gears until both spider gears and washers are free.
-Remove the side gears and washers.
Installation is opposite of removal. It may take some trial and error to get the gears all back together properly. Also, because the axles were pulled you may have damaged the outer axle seals. Some people recommend putting RTV around the seals, I can't comment on that method as I haven't done it myself. Also, Jeep instructs to use new axle retaining bolts and nuts after removal instead of reinstalling the old ones. Those can be hard to source. At the very least I would recommend putting loctite on them if you reuse the old hardware.
If someone who has more experience with the D44 could clear up, you might be able to get the gears out without pulling the axle shafts (which would eliminate like half the work required). However, I don't think there is enough room inside the carrier to get the side gears out without pulling the shafts back at least a little bit. Again, if someone with more insight on this could comment that would be great.