No no no, the diodes are nothing to do with noise!
This is a completely standard limit-switch circuit, each limit switch is normally closed, but opens when
the limit is reached, cutting off the current to the motor only if its travelling towards the limit. The diodes
allow the motor go the other way, back from the limit, even though that limit switch is open circuit.
The circuit has boxes marked "NFU" - not knowing the function of these its hard to say how to drive
these, I suspect the abbreviation is for "N??? Focus Unit", and it may be these have some electronics,
or may just be names for the sets of wires.
If they are just names you simply apply 6.4V or thereabouts to a pair of wires and the motor will move
until the endstop and stop. Reverse polarity and it moves back to the other endstop and stops. The
motors are very low current, note, 40mA rated (stall current will be more of course, as always).
If the NFU boxes represent some active circuitry it may complicate things. I'm not sure what
circuitry this could be.