I would have done something like this...
-Spider-Man swinging, everything's fine--no webbing. He falls--
Doc Ock (voice over): Ladies and gentlemen, fasten your seatbelts.
-Peter Parker trying to get to class, gets hit in the head with the bookbag.
Peter Parker (voice over): I have this friend who keeps having these dreams...
-Peter talking to Doc Connors about how he's always late for class
-JJJ firing Peter
-MJ asking Peter if he loves her.
Peter (voice over): ...and he dreams he's Spider-Man.
-Peter pulling on his mask.
-Doc Ock in his lab.
Doc Ock: ...and now may I introduce my...assistants.
-He throws the sheet back, revealing the tentacles.
Doc Ock: Impervious to heat and magnetism...
-He puts in the tritium. It creates a miniature sun.
Peter (voice over): ...and (in the dream) he keeps climbing walls and falling.
-The sun's gravity begins drawing things in.
-The windows explode, killing Rosie.
-The tentacles are fused to Ock's spine.
-Ock at the pier, looking into the water.
Doc Ock: My Rosie's dead...my dream is dead...I miscalculated horribly...
Peter's Doctor (voice over): Maybe your friend's not supposed to be Spider-Man.
Doc Ock: I couldn't have miscalculated. It was working...
-Peter looking at his not-web-shooting hand.
Uncle Ben: All these things you're thinking about...it's making me very sad, Peter.
-Spider-Man vs. Doc Ock in the bank: Spidey tries to shoot a web, Ock nails him with the moneybags.
Doc Ock: Ha!
-A couple quick cuts of the train fight, nothing too revealing.
-Ock snapping the tentacle claws in Peter's face.
Uncle Ben (voice over): Remember Pete, with great power, comes great responsibility.
-MJ bowing her head in sadness as Peter tells her he doesn't love her.
Peter (voice over): I want a life of my own.
-Several quick cuts:
-Ock and Spidey fighting, Ock gaining the upper hand.
Doc Ock: You've spun your webs in my business for the last time!
-Ock throwing Spidey from the train. Cut to black.
Peter (voice over): Who am I?
-Spider-Man swinging into camera.
-Ock turns--they both get knocked over the edge of the train.
Cut to black again. Show release date.
Off the top of my head, that's how I'd do it. But that's more of a trailer than released scenes, so...
I'd release the clocktower fight (before they land on the train, end with them falling)
and the scene where PEter tries to talk MJ into marrying him even though she's engaged.