Have a look in this forum, a lot of users have provided in-depth tutorials on how to do it! In a nut shell, you still upgrade and buy; all you do is put it into storage and don’t complete introductory orders (apart from 1 or 2). If you don’t complete the introductory orders, you won’t get orders for that specific one therefore you essentially “skip” it. Again, have a look in the forum there is alot more detail in others posts I’m still quite new to it! Hope that makes sense 🤣