Print version https://www.m109riders.com/howto/ujoint/
This has to be the hardest job to do if you try and stab it from the back of the swingarm. If you can do it that way you need to go buy a lotto ticket because you are one lucky guy. This is how I had to do it and so did a another member here.
First thing you need to do is to pull off the left chrome side covers to access the Secondary Bevel Gears.
Remove the speedometer sensor bolt and remove speedometer sensor and place out of the way.
Remove the four bolts holding the Secondary Gear housing.
You're going to lose a little oil on this so put something under the bike so you don't make a big mess.
Now just pull the housing towards you and pull out the u-joint.
Now you can bolt the Final Gear Case back up into the swingarm.
Install the u-joint on to the driveshaft. I still had a hard time getting this on so there is no way I could have done it the other way.
Now that you have the u-joint on the driveshaft you need to put the spline back into the gear housing and fish it all back in. What I did was loosen up the Final Gear Case so that it would give me some room to put the case back on. It's a tight fit so you need all the room you can get.
That's pretty much it after that. All you need to do now is put all the bolts back in a tighten them up and you're done. That wasn't so bad was it?