PLEASE DON"T BUT THAT POOR LITTLE ALUMINUM CASE IN A PRESS. I also doubt that heat will work, as heat is going to expand all the metal, including the bearing race. Crank's come out really easily with the proper tool. Years ago, I purchased a harmonic balancer puller from a used tool store. It looks like a long thin "H" with a big screw right in the middle. Because the space in the top and bottom part of the "H" is so wide, I was forced to use 3/8" bolts. However, you will notice that no where on the case will a 3/8" bolt thread in, so I cut the threads off of the 3/8" bolt, center drilled the end of the bolt, and taped the hole for a little 8mm bolt that will screw into virtually all of the holes in the case. Once the hole was taped, I purchased a long 8mm bolt with lots of threads, cut off the head, and screwed/loctited the threaded section of the 8mm bolt into the taped hole.
Now that the press is ready to go, simply center the large press screw over the center of the crank and find a hole in the case that is directly under each end of your press. Don't be affraid to remove a bolt in order to find suitable holes that are 180 degrees apposed. If the two holes you are going to use are at different depths in the case (for example, you are using one hole for the clutch cover and one hole for a bolt that holds a bearing in place down inside the case), just add a few washers between the head of the 3/8 bolt and the press to compensate for the difference. The idea here is to hold the press scress perfectly in line with the crank. Also, make sure your new custom bolts are screwed in all the way. You don't want them to be able to wiggle at all, as you risk damaging the threads in the case.
Once your press is install, tighten the center press screw and the crank will push right out of the case.
On the bearing removal, you must use a clamshell type bearing removal tool to get between the bearing and the crank. As you tighten the clamshell, the bearing will begin to move off the crank. Once tight, use a press to remove the bearing.
A word of caution: NEVER USE A HAMMER ON YOUR CRANK. The lone exception is to tap the end of your crank after initial installation to relieve the bearing bind and help center the crank. I learned this lesson the hard way, as I once use a hammer to assist in crank work (this was long, long ago). The result was that I actually distorted one crank end just a few thousands. Have any idea what a new crank cost?? I do, and it's not cheap. It's about like purchasing a new cyliner, but worse. In short, don't use a hammer on anything but the end of the crank, and then only use a dead blow hammer just to set the crank after initial installation.
On the crank seals, I have pulled so many motors apart over the years, I've lost track of which models allow seal replacement without splitting the cases. It appears the 500 requires case splitting. Yuk, I hate that job, as it tears up an entire Saturday! Oh well, there's always Sunday for riding...
Rick