Not sure if it is as simple as inserting the sub-projects into the master project (Project tab / Subproject)? This will give you all projects combined into a single project. If you are new to this I would initially be careful before saving the master project and sub-projects as a single unit. Some basics like not moving any of the projects is the same as using external links. I just might do a little searching online to get comfortable is all. Let me know if it is more than that. Hope that helps.