I think the trick here is not changing the existing story and themes around too much. Kirk's death could be more heroic and mirror his first "death scene" just by reversing the order in which the Enterprise was destroyed and Soran was defeated in the last ten minutes or so of the movie.
Picard and Kirk defeat Soran. Picard contacts the Enterprise, and Riker tells him they are under attack. Picard says to phase the shields and transporter and beam him directly to the bridge, he then glances over at Kirk who looks at him and says something like, “Well, I’ve come this far -- ,” or “In for a penny -- .” Picard nods and says to make that two to beam to the bridge.
Picard and Kirk materialize on a bridge that’s hectic with action and taking punishment. Riker comes up to the two, stares for a moment at Kirk as if he’s seeing a ghost, then snaps out of it to inform Picard of what is happening and what their plan is. Kirk is looking around the bridge taking it all in. His eyes fix for a moment on Worf at his weapons station, who gives him a “what are you starring at?” look. Kirk’s attention then turns to the view screen and the bird of prey spraying fire at the Enterprise. Picard tells Riker to implement the plan, and it works as it did in the original story. The Klingon ship is destroyed.
Before there is any time to celebrate, Geordi informs the bridge the warp core is going to breach in about ten minutes and there’s nothing he can do about it. Picard issues an order for all crew to be evacuated to the saucer section and to prepare for separation. Amid the commotion, Kirk just stands there, feeling more helpless than he felt on the bridge of the Enterprise-B.
Data informs Picard that a branch of the nexus is approaching fast, and if they get caught in its gravimetric field, they won’t get away. Kirk suddenly snaps to life. He asks Picard if the weapons systems still work. Picard looks at Worf, who says they’re out in the saucer, but work in the secondary hull. Without saying a word, Kirk bolts to a turbolift, enters, and instinctively says, “secondary bridge” after the door closes. He exits into a corridor and starts fighting upstream against the fleeing crew. He enters the secondary bridge, identifies the weapons system, and puts it online. Picard hails him about what he’s doing. He tells Picard that he has it on good advice that if he can fire several photon torpedoes into the nexus, it will distort the gravitational field enough to buy them time to escape. Picard tells him he won’t have time to get out. Kirk tells him to lock a transporter beam onto him, and beam him out on his command after he’s fired the torpedoes.
Geordi informs Picard everyone is aboard the saucer. It separates, but the pull of the nexus has already made it impossible to get away. On the viewscreen, Picard sees several photon torpedoes exit the secondary hull and enter the nexus. There are bright flashes of color, then everything in the nexus slows and it grows dim. Data informs Picard that the pull of the nexus has been neutralized. Picard calls for full impulse power then yells for Kirk to be beamed out, but as he finishes his words, there is a large flash on the viewscreen that attracts everyone’s attention. Part of the nexus hit the secondary hull at about the same time the hull blew up. The transporter room reports it lost its lock on Kirk. There is silence on the bridge, broken suddenly by Data yelling, “Oh, shit!” Picard spins and looks at him. Data says that while they are free of the nexus, the force of the blow of the secondary hull has knocked the controls offline and they are careening toward Veridian III.
The Enterprise saucer crashes as it did in the original story, but with Picard in the captain’s chair. As the ship stops, the screen fades to black, and when it comes back, it’s obvious some time has passed and the crew is scouring the saucer for whatever personal items they can salvage. In an ending similar to the actual ending, as they await rescue from the Farragut, Riker and Picard are on the bridge as Picard looks for his photo book. In their conversation, Riker laments the loss of the ship and notes the bravery of Kirk in giving his life for the ship and crew. Picard remarks that they thought that eighty years ago too, and they turned out to be wrong on one point. He wasn't dead. Picard says he wasn’t going to make the same mistake, and Kirk is officially listed as “missing” in his log.
That ending creates some ambivalence about Kirk’s fate, too.
