If the front shafts are retained in the diff the same way as the rear your gonna need a good slide hammer. By good I mean BIG. The shaft is splined in the diff and held in by a snap ring. None of which gets any oil from the diff. Mine were rusted badly. So much that I opted to replace the splined stubs on both sides.
Also make sure to clean the splines in the diff real well with a pipe brush or something similar. I had to clean the rust from between the grooves with a long pick and file. Apply liberal amounts of anti seize on assembly.
If you have the time I would remove the other side and clean and antiseize the splines as well. Once you get one side apart the other side can be soaked in penetrating oil thru the diff while you work on your boot. Then you can drive the remaining shaft out with a long drift punch and a bfh. Preferably something softer like brass or aluminum. This is much more effective than using a slide hammer, much energy is lost in the knuckles. You really need a good solid crack to break things loose. At least I did.
You can also use straps to remove the axle, less stress on the diff and bearings. There are a couple YouTube videos on how to, but basically wrap the strap around the axle end next to the diff , wrap the other end to the lower A Arm end with it in its highest position. Grab the end of the a arm (lever) and push down (the strap will work as a puller) you can quickly push the arm down or hang off it if the straps are not in the correct position it basically creates a bind so making the strap come off the axle at 9 and 3 is important. I have 2 new rear axles I'm going to put in after the summer. So right now I have sprayed the diff and axle ends with Kroil (better than PB Blaster IMHO) in a couple months, I expect I'll be able to just tug em out with ease, as the fronts did. I have given up trying to float the thing in mud and water.... The Rincon just wants to go fast mostly, and wallowing does so much damage to the spinning stuff)