Driving ULN2064 with 74HC595 for 12V motor loads
Question : How can i drive ULN2064B with 74HC595 as "H BRIDGE" ???


You can't, neither with ULN2803. This driver is not a H-bridge driver.
The stepper motor would require a chopper (current limiting) and not a simple buffer. For simple applications you may use ULNs to drive unipolar stepper motor, but with low voltage and low speeds. \$V=I_{rated}\cdot R_{coil}\$.