HO Kato Gunderson Maxi IV cars

I recently purchase two sets of these cars. They seem to be really nice and roll pretty good.

My questions are what is the procedure to change over to Kadees and how do I take the trucks off if I want to weather them?

Thanks in advance.

Will,
I have a set of those & I looked them over a bit, here is what I did;
On the End cars I was able to grasp the trucks by the truck springs to wiggle & work them until they popped out.
I then unscrewed the coupler boxes & put in Kaydee 158 Scale Whisker couplers. They looked like they may be loose in there, but once tightened back in place they worked great.
I popped the trucks back on, noting their direction, they fit one way only.
For the Center trucks it is more of a challenge, I found that finding & camfering an appropriate sized brass tube will let you make a tool to help depress the clip tabs to coax the trucks from their bases. One of my bases came out with the truck, but that was OK because it was easier to seperate & replace the base before replacing the truck.
Hope that helps!