Sm 456

[Ride_drz]

So Im sure there has been lots of talk about these transmissions on here but I dont know if its my browser or what but it wont let me search anything on the search functions. So my main question is how hard is it to rebuild one of these, where can I get a kit, and what can I expect. The trans now works pretty alright, dosent pop out of gear but when I changed the fluid last summer I pulled chunks of thin metal out of the drain plug which im thinking was the sincros.
the main reason for doing this is to replace the seals and basicly to go through it for my own peace of mind. Im also looking to do the exact same to my 205 transfer case so any info on that would be awsome aswell thank you in advance