removing half shaft 1996 caravan

I have a 1996 Dodge Caravan that needs a left front axle seal but I am unable to get the half shaft off. My repair book says to place a pry bar between the trans axle and the shaft and strike it with a swift blow using a hammer. I have tried this procedure repeadly with out success. My arm is getting sore from swinging the hammer. I replaced the right side seal without a problem, however the left side half shaft won't give. Does someone out there have a different approach to removing the half shaft? Thanks in advance.