Well, I wouldn't take ALL of the dihedrahl out of the wing. You probably won't like the way it flies if you do. A little dihedrahl is good for a high wing trainer.

But if you want to do it, you will need some hard plywood. I don't know if this is a KIT or an ARF. If it's a kit, just build it per plans and then cut a new dihedrahl brace from the hard plywood with the angle that you want.

Or you could get another hardwood block- maple or oak- and cut it to the angle that you need.

Sounds to me like this is one of those wings that has a pocket which the dihedrahl block slides into. If it is, then just buy the hardwood block and cut it to the angle you want. Make sure you use SLOW CURE epoxy (30min) on the joint and put a LOT of epoxy in it when you glue it together. The epoxy should be running out of the joint when you push the block into the pocket. Coat the block with epoxy before you slide it in, and fill the pocket with PLENTY of epoxy. Spread epoxy on the two ribs also.

It's handy to have a bottle of rubbing alchohol around and a few of those red shop towels when your doing this. Get one of those shop towels soaking wet with alchohol and use it to wipe off the excess epoxy when it squirts out.

I can't stress it enough---you MUST have the pocket and block completely covered with epoxy and it should be squirting out when you slide the two wing halves together.

So what if you waste $3.00 worth of epoxy and spend $5.00 on alchohol and shop towels.

How sad are you gonna be if you crash your plane because the wing joint failed due to not having enough epoxy on the joint?

I have seen MANY MANY planes crash because of wing joint faliure at the center joint. Most of the time it is because the modeler didn't use enough epoxy.

If your changing the dihedrahl to get the plane to perform better, you might want to take this into consideration-----If your tired of trainers, and want a high performance plane----then buy a higher performance plane and leave the trainer in the shop.

But, have fun and do what makes you and your wallet happy.