What exactly do you mean it kicks in and sends you through the window? If it "kicks in" you would experience a "power slide".
It's actually a really cheap fix....but will require some skill.
The third member, or carrier needs to be removed from the rear axle. That's where the easy part stops.
You then have to disable the 3rd member, remove the LSD and replace with an open carrier. You can probably pick one up dirt cheap on craigslist, through this forum or a junkyard. You then have to rebuild the 3rd with the new open carrier. Rebuild kits run about $100.
Another option, see if there is someone on here that would be willing to trade their open diff for your LSD diff. No need to rebuild and you could probably make a few dollars in the deal, since the LSD diff would be more sought out than an open diff.
Good luck.
You can find a full write up on rebuilding a Toyota 3rd here:
http://www.4x4wire.com/toyota/