89 S10 Blazer TransferCase fluid change

My Blazer has 190,000(4.3) and Im not sure when or if the transfer case fluid has ever been changed....

Im not the most Mechanial guy but, I do know some about repairs but, this is my 1st 4X4 and I ve got alot to learn about mant of them...

Is this something i could do fairly easy or do i need the services of a mech?

If I can do it whats involved and whats the best Fluid to use?? I want to go Synthetic in there...Ive made the change over in motor and love it so far...

I also need to do the Tranny but, thats another days work...