Will it be possible for one to change from a student visa to a "one-man" business visa. The business is a one-man (handiwork) business. It is a hobby of mine that I can use to make a product that some German stores are importing from China. I am asking in light of the information about changes to immigration laws come March 1, 2020. (https://googleweblight.***/i?u=https://***.make-it-in-germany.***/en/visa/kinds-of-visa/work/skilled-immigration-act/&hl=en-ZA)