Star Trek: First Contact (1996)

Answer: It was never shown or explained how they landed, so any answer would be a guess. This is set in the future (mid-21st Century), so there could have been new rocket technology.

raywest

Answer: While the main fuselage was a re-purposed intercontinental ballistic missile, and they separated from the ascent stage of the rocket, the payload section housed two deployable prototype warp nacelles capable of achieving lightspeed. Beyond that, the payload also contained the prototype warp core (which was powered by matter/antimatter annihilation), the warp core coolant, elaborate magnetic-containment systems, and probably even impulse drive and landing thrusters (It kind of goes without saying that thruster and impulse technology would have existed before warp technology). There was no space left over in the payload section for conventional rocket propellant, and Zefram Cochrane's enormously-expensive and one-of-a-kind warp components would not be expendable; so he must have devised a way to safely bring the Phoenix down for re-use. Since the Phoenix's return and landing were never addressed in the film, my assumption is that the payload section was powered entirely by the warp core, including its impulse drive and landing thrusters.

Charles Austin Miller