I pre-purchased the modules in the bundle to get them done. I gave myself a month for each module but you could probably do it more quickly if you wished. They are open book, not proctored so not so bad.
The actual CPC exam I felt was extremely easy compared to all the other examinations and to be honest after its all said and done, I felt a little cheated that the last exam was just fluff and focused on mainly the most basic of questions for each of the main topics. I would say of all the exams its definitely the easiest. I gave myself 3 months to study and take exam but I didn't need it. You almost don't even need to read the CPC book if you studied for all the other materials, you could pass without reading.