It is not hard unless you plan on replacing the seal & bearing then a press is required. I just did. Once opened up if the seal & bearing are good it is usually just wear plates impeller & maybe a cam. That pump new is a lot of money and it should be good for over may years without a complete rebuild.
Those pumps are very easy to rebuild. Larry is right if you do a major rebuild which includes bearings you will need a light press. You can pick up a small press up at harbor freight for 125-150 bucks that will do the job. One rebuild will pay for press and then some!
Last season I had the shaft on one of my pumps just snap. In the middle of tuna season so I did a core trade for a rebuild but at $750 I'm grtting one of these Seamax pumps as a spare. Can anyone say they know they are better?