Hunt the rut. Kill a doe and cut off her glands and steal her piss. Use a true talker and the can. Put a decoy out now and cover it with a canvas bag hung from a rope that you can lift from your stand. On the right day, dump the piss, hang the glands, take mama out of the bag and start calling him in.
If that doesn't work, get your buddy to stay at a close distance again this year, doing something that keeps the big-boys attention and then sneak up on him and kill him. Shoot him with an arrow, drop the bow and chase him down. You need to be running now to condition yourself. With any luck he'll run somewhere that your buddy can see you jump on him and stab him to death.
Don't be scared of the killing part, it's natural, but your buddy might think you're a freak!