OK. I'm assuming you're asking how to adjust the chain? There are two long bolts attaching your carrier to the swing arm. One above the carrier and one below. Loosen those two bolts. Next you need to tighten the two adjustment bolts on the bottom of the carrier/swingarm. These are the two bolts inside of the clamps. After you tighten those bolts (causing your carrier to roll and your chain to tighten), tighten everything back up. This should take care of your chain.
Your e-brake has nothing to do with this problem. It is a bad set up. My advice is to remove the whole damn thing and install a block off plate.