I think it's easier to send the Enterprise-D back in time than send Kirk forward. Have the Duras Sisters betray Soran, take his weapon, and travel back in time, to when the Enterprise-B launches, attacking the ship on its maiden voyage with most of the TOS cast aboard. The Ent-D arrives in time to fight them off, but the damage has been done. Harriman and a lot of his senior officers are injured, the Ent-B is damaged, and the TOS cast has to take over. Picard and company offer to fix the damage, but Kirk talks to Starfleet Command and they tell him that they want him to hunt down the Duras Sisters with the Enterprise-D to ensure that the timeline isn't altered and the recent peace with the Klingons isn't jeopardized. So Picard has his crew help repair the Ent-B and fix it up to fully operational status so the two crews can complete the mission.
Meanwhile, the Duras Sisters discover that Soran's weapon isn't ready, so they hijack an old station inside the Klingon-Federation Neutral Zone, and cash in some family connections with Houses that aren't too thrilled with the recent peace, so they have a small flotilla around to defend the station. The Enterprises show up for the big fight, with Riker piloting a runabout close to the station to drop off Chekov, Worf, and a bunch of Ent-D security guys. The Enterprise-D blasts some of the smaller ships, but is hampered by defending the Ent-B from the ships and the station, which is firing on both ships with pretty powerful, but slow firing disruptors. Worf and Chekov's team gets pinned down on the station, so Kirk beams over with some Ent-B security folks to help them out. In the process, Worf kills one of the Duras sisters (whichever one he hates most), while Kirk hurries to destroy the Duras' weapon.
Kirk gets there and makes a terrible discovery: there's no way to set a timer and leave. He has to stay... and he knows this is the moment he dies, because he's totally alone in the room. He warns the Enterprises to get their people off the station, then detonates the weapon as Duras troops try to break into the room. For an instant, space around him distorts and he can see the cosmos, due to the weapon using gravitational effects, then the station blows up and takes out the rest of the Klingon flotilla. The memorial service for Kirk is held on the Enterprise-D before it returns to the future, while in the past, Starfleet officially declares that Kirk died fighting Klingon terrorists... until the Enterprise-D returns from the past, and Starfleet can set the official record straight.