Embarassed to say I've been an auto mechanic for 20 years, butdon't know how to change the oil in the trans on my '99 883? Havent really looked at it yet, but I dont know much about bikes.

 

There is a drain plug on the primary side towards the back of it. Open it up and let it drain .You may have to put the kickstand on a 2x4 to get the bike more level. To fill it add 32 oz through the primary chain inspection cover. If it has not been removed in a while, use a straight allen key and give them a good wack so you can get them out , or use an impact driver . Thats it .. Mark...

 

Go easy on the gasket and you can probably reuse it.