Would you have to travel faster than time to travel through it? And if so how fast is that?
If you accept the ideal that time is a continuum that all matter moves through. Then it does not matter if the continuum is in notion are not unless it is in non uniform motion. Time travel can be accomplished by accelerating one's own rate of propagation relative to the rate of propagation of the other matter in the time continuum. Before we can change the rate of propagation we must undestand the mechanism by which matter propagates through the time continuum.