I've just finished the 120 hour TEFL course. It's taken me several weeks of working quite intensively through the lessons each day. I wouldn't say it's especially difficult. Everything is really well structured and the lessons include lots of explanation and examples. However, there is quite a lot of content to work through.
I would suggest you set aside 2 hours per day to work through a whole module so that you get the whole picture of what's being taught in one go. So that would mean going through the whole module for teaching speaking to students, or the whole module for motivation techniques etc. I found this helped me keep working through them at a steady pace.
After finishing the lessons you face an assessment with two parts. The first part is a test which covers questions from each of the previous modules. It took about 40 minutes for me to complete. After that there's an assignment where you need to create a lesson plan and some classroom materials. I wasn't really looking forward to this part of the assessment but it was actually a lot of fun and now I can see how important it was to do.
My assessment was marked within 4 days and I received a pass, along with some feedback on how well I did and what I could have improved on.
After passing the TEFL course, there's also another course which opens up and contains a downloadable CV template with a guidance for teaching passing interviews and giving demo classes. The course staff have also reached out to me and have started to arrange some Skype interviews with schools in China. It seems there's some options available in Beijing with offers of around 14k chinese yuan / $2100 which is exciting so far.