If you cant find a guide and want to try, try on the right side of where the canal dumps into the lower lake. There is a sand and gravel flat there that holds them year round. It is shallow so mind the stumps. Try to fish in the 3-6' range with the split shot and worm rig right on the bottom. You will likely see several boats there doing the same thing. Those Asian clams are good for bait but the very best are little crayfish 1-2" long. Red worms and crawlers work also and are a lot easier to get. Don't be surprised if a blue cat runs off with your tackle.

Good Luck.