combining articulate courses

I have an SME that created 4 separate Articulate courses, before getting the go ahead from my team. He has completed all of these and recorded audio, etc. In a recent team meeting we discussed how it would be better if these were in 1 big course instead of 4 separate modules. Is there an easy way to combine these? I have thought about it and the only way I can think to do it is combine all of the slides in one PowerPoint then go to each separate module export the audio then import the audio into each slide in the new combined course. Which will be a pain but I can't think of another way to do it. Also the course will be running on an LMS so I can't link from 1 separate module to another or create a "main menu" to link to each module. Any ideas?