I would torpedo the Kobayashi Maru, destroying the ship and killing all aboard - then state to the Klingons that the crew of the Kobayashi Maru was a renegade ship intent on sowing the seeds of distrust between the Federation and the Klingon Empire. I would then entreat the Klingons, in light of my actions, to a potential peace treaty.

I would enter the neutral zone with all shields down and all weapons deactivated. And would not activate them no matter how much tempted. Before entering the neutral zone I would declare openly why I have to enter the neutral zone and ask Klingon assistance for saving the crew. I believe Klingons are too honourable to destroy a ship which would not defend itself. If everything went wrong at least Klingons would not have any excuse to say that Federation first broke the agreement.

I would turn and run for a short while and as the Klingon ships on my flanks moved to encircle me I would suddenly turn and pump a volley of fire into the nearest flanking ship's engines, then hit warp again in the direction of federation space with the SOS going full blast. Hopefully the two other klingon ships would be caught off guard and I'd get a good lead on them.

Pars that approach might work with next gen klingons though i wouldn't personally want to trust to it. against the klingons of kirk's generation at best that would get you boarded and your ship seized more likely summarily blown up once they were sure it wasn't a trap of some sort.

I would leave it up to the Organians to sort out since they supervise the neutral zone. but if I was to cross to rescue then I would expect the Organians to enforce the treaty they made the Federation and Klingons to make by rendering hostile action by any vessel impossible.. after all, they are all powerful Q types.