The rebuild manual is available online and it will tell you how to open it up. Check my signature, or BillB's Techno Site.
Short version - remove shifter, drive roll pin in shifter block straight down, remove tailhousing bolts, slide tailhousing off (hold hand over shifter block - there is a spring and ball you can lose if not careful), remove top cover bolts and remove cover. To reinstall, basically reverse, but you have to pull the roll pin out and drive it in from the top again - it has to be set in there and held by hand while you reinstall the tailhousing.