The horizontal monitor should be sitting on a shelf, so you would need to do is disconnect the power connector (Molex connector?) and the video signal connectors from the chassis. There are probably 4 bolts holding the monitor down to the shelf which will need to be removed. I wouldn't worry about discharging the monitor, just stay clear from the red anode wire going into the top of the tube. I won't say that the tube is totally discharged or not, but if it hasn't been turned on in a year or two like you say, the chance of it retaining any charge is extremely slim.
There are probably hand cutouts on the monitor frame, so after you disconnect the wires and remove the bolts, you should be able to lift the monitor right out.
I'm not familiar with that particular control, but I doubt it is optical. Probably an analog control. If you can post some pics of the underside of the control, I'm sure someone can tell you if it might be compatible with an Opti-PAC.