Super easy, a little pressure to one side and the old ones pop out, installation in the reverse move. On a side note, I tweeted ER about their wheels, they told be they were about to be released 4 months ago. They are promising a more prototypical profile front and back, I'd love to see it happen (soon).
If they look anything like the HO wheels ER has shown at trainshows, they will be impressive. However, paraphrase Donald Sutherland in The Dirty Dozen, "Very pretty, but do they run?" The proof will be in the running. Andy Tetsu Uma
With the exception of the center bearings are Kato 93040 and 93045 the same wheel set? http://www.katousa.com/images/932040.jpg http://www.katousa.com/images/932045.jpg The 932040 are included with the Kato Amtrak 800073 silver trucks.