To become a credited ACMG assistant or full ski guide, you have to know quite a bit more than just skiing. Tonnes of knowledge and experience required in things like navigation, glacier travel, avalanche related stuff, rescue, survival, client care etc.
Definitely a very long process. the best thing to do would be to visit the ACMG website and take a gander at the credentials needed as pre requisites for the ski guiding exams. Then, quit your job and go live at a cabin in the mountains for 10 winters doing nothing but skitouring.