If you are doing it at your house with jackstands, probably around 3 hours if you have never done one before. If you had a lift at your disposal you could have it done in less than two hours. You will need a decent selection of tools, like a variety of extensions and swivel sockets for taking out the bellhousing and starter bolts.
it's not hard too do... you may have too heat up the manifold to h-pipe bolts too take them off without breaking the studs... a mapp gas torch can do that..