I used to do that for a living for 3 years at the Royal Brompton Hospital here in London. It was an amazing job, loved it. Worse thing I had to deal with was an exhumation for a second opinion on her heart. The skin slippage was gros and the smell stuck to me for hours! Saw a train hit victim too.
I used to also lay them out for relatives to view and release them to undertakers - the undertakers used to give me really good tips! (money that is)
Pathologists did the diagnosis but I did the dissection and re-assembly afterwards. Toughest part for me was putting my hand up the neck, cutting the tongue ligaments and pulling it, the throat organs, heart and lungs off the spine in one block(called "the pluck"). Was just really fiddly!