When the coil of the latching relay it is momentarily energized, one contact and the common are closed and stay closed even after the coil is no longer energized. When it is momentarily energized again, the other contact and the common are closed.
For each actuator, connect one motor lead of the actuator to #30 of an SPDT relay and #87a to ground. Connect the other motor lead of the actuator to a second SPDT relay and wire as above. On the first relay connect #86 to one of the contacts (non common) of the latching relay and connect #86 of the second SPDT relay to the other contact (non common) of the latching relay. Connect #87 and #85 of both SPDT relays and one side of the coil of the latching relay to 12V+. Connect the (-) output of one momentary switch to the cathode sides of two diodes. Connect the anode side of one diode to the other side of the coil of the latching relay and connect the anode side of the second diode to the common contact of the latching relay.
When you press the momentary contact switch, the motor should move in one direction for as long as you hold it and stop when you release it. When you press and hold it again, it should move in the opposite direction.