Start off small. Think of some really neat topic in your curriculum that you enjoy teaching. Ask your class to create a list of questions that they have always wondered about the topic, or ask them to create a mind-map of ideas or questions they associate with the topic. Then, ask them to think of ways you might explore together. You, the teacher, will be learning along with them. (As an aside, I can honestly say that in my classroom we have now tipped the balance: the students end up teaching me more than I teach them on new explorations. After all, there are 27 of them researching and writing, and only one of me.)
Gather some simple materials to get started. Show a few videos, read a few books together, or take a field trip to build some excitement and background knowledge. This gives you lots of time to determine what mini-lessons you might want to include (we are responsible for a curriculum, after all). Now the real fun begins.
Set up some teams or groups in your room and give them fun names. Mix and match like crazy and don't worry about setting up just the right combination. The students will all bring something to the table that is going to build a satisfying whole. Create a rotation of activities that the group can rotate through and make sure of one vitally important element: every group presents their work to the class. The students will feel the excitement of preparing to teach their peers and rise to the challenge, I guarantee it. They may stumble and hesitate, but end result will be that their work has an audience, is appreciated, and is the stepping stone for greater success down the line.
See, it's not that hard. Get started today!