To make compost tea you just need a covered container, compost, water, and time. I use a cotton pillowcase or a square of unbleached cotton. I move the bundle up and down a few times whenever I walk by the container.
More generally, the terms exergonic and endergonic relate to the free energy change in any process, not just chemical reactions. An example of an exergonic reaction is cellular respiration. By contrast, the terms exothermic and endothermic relate to the overall exchange of heat during a process.
In order to release this energy, these chemicals must undergo exergonic reactions. Exergonic reactions are chemical reactions that release energy in the form of heat. Typically, this energy is released when bonds are broken.