Finisher dive vs. standing Opp.

Are you speaking of the create-a-finisher Dive trophy?

Or just in general, doing a diving finisher vs a standing opponent?

1st - create a dive finisher, doesn't have to be difficult, then go into a singles match, & perform it - trophy unlocked. Creating them is easy as hell. They're not very fluid, and pretty useless really. So just click on the first options you get, then take a look in the wrestler selection part @ the requirements for the finisher, and set out getting said requirements in the match, then climb up the top of the TB & pressed the finisher button.

As for doing any old dive finisher vs standing opp. These can be harder, but I've always just beaten the pulp out of the opp. & then dragged them to a TB whilst I've got a finisher, stood them up so they're faving the TB, jumped up, and bam - easy as pie.

If you mean the one on THQ Training Facility, then first go to Training Options and put the A.I. Difficulty to None so your opponent won't move, then the Momentum Setting to Finisher (so you have your finisher ready). The superstar you're using should have a finisher wherein your opponent is standing up while he is on the turnbuckle.

Edit the superstar's finisher in Create-A-Moveset to something like "Diving Clothesline" or "Diving Spear" and that should do it. Then climb up the turnbuckle and execute the move by pressing Triangle.