I only had the pleasure of visiting the insides of my EL-7 the one time but removing the hubs was necessary. If I remember right, the face plate must come off and that exposes holes directly beneath the hubs. There are set screws holding the hubs on the shaft and those holes allow access. I also think I recall there being two set screws per hub - 90 degrees apart. . Loosening them requires a very small hex key/Alan wrench. It is smaller than that I use to remove knobs from potentiometer shafts. I had to buy a set of small hex keys from an RC hobby store in order to get one that small. It was nearly too short to reach the set screw but there was just enough to grip with a pair of pliers in order to turn it. You will need to unfasten the back plate of the cassette well. Not actually take it out, but provide sufficient "wiggle room" to get the hubs out. Good luck with your project but I recently read that the EL-7 is easier to service because there is no mechanical linkage. Maybe do that one first?