Reset signals are just a clock pulse, but there's not an easy way to accomplish this with the regular MB2. You could maybe use the velocity or modulation track signal and shape it into a pulse if you have the right eurorack gear - but then you would be eating up a track. Velocity is just a control voltage active during the duration of a note, so that might work a pulse - but I think with the MB2 every entered step has a velocity. You might be limited in what you could do here. I would experiment with those first probably. Try setting a full modulation on the first or last step, or seeing if a specific velocity amount will trigger a reset.
If you have a midi module that accepts and copies a reset signal that might be the easiest.
