They covered it a little bit in the Bas Rutten DVDs.
Press him up against the fence, and lean into him while getting double underhooks. From here he's pretty much glued. If he's keeping his legs close together, knee the inside of one of them and make space. Now take your right hand and reach down to his left ankle, while pulling up on your left underhook. Pick that ankle and down he goes; hard too.
You can also try an Ouchi Gari (inner leg trip) from there. Or just try basically any takedown off of the fence.
On the ground, if he has guard on you, you can press him up against the fence and start GnPing him. Buuuut... I'm starting to dislike this. It works, but it makes the fight pretty boring to watch. Just pinning him there. You'll get a win, but I'd rather use more skill and make the fight more exciting.
I guess basically it comes down to, you want him against the fence, and you don't want to be against the fence.
If he puts you against the fence, get off of it. Whatever you need to do. BUT, if you're on the ground, and you're being pressed against the fence, watch your legs when you're using them to adjust yourself. Sometimes you can leave yourself open to a leglock if you get too crazy with your legs.
