I’m a little confused since you say you are a product designer already. Industrial Design and Product Design is pretty much the same thing, I’m assuming you are doing mostly Packaging Design then?
I made a jump from Art Director to Industrial Designer about five years ago, so here’s my advice anyway:
Learn either Pro/E or Solidworks. Rino is OK, but the advantage that the other programs have besides being about a million times more robust is that they are widely used in the industry. Plus, it will help you get a foot in the door. You may wind up doing some “CAD jockey” work as your first form of employment, which is perfectly OK, since you can learn a lot of valuble stuff from temporary CAD jobs.
Second, educate yourself. Read about the profession. Read about sketching techniques. Read about manufacturing teqniques. All the info you need is out there if you look hard enough.
Third, design like crazy. Its like learning an instrument. The more you put in, the more you get out. Try to stockpile as much ID work as you can because you will need it for the fourth item on the list which is…
PORTFOLIO!!! This is your gold key into the design field. A great book will get you places faster than anything. This is a creative field. Only so much can be taught. The rest is talent. Try to make a well rounded book with sketches, renders and hopefully even models and prototypes. Cover different fields like electronics, toys, furniture, houswares etc. etc.
You could also enroll in a design school, but this might be difficult if you are already in the workforce and have bills to pay. Plus, piling up a mound of debt in exchange for a degree can be hazardous. There are plenty of ID graduates that are unemployed. My personal feeling is that while it may be harder finding work without an ID degree initially, it isn’t impossible. Plus, once you are in, you can blaze your own path to glory.
This is a long winding career, so be patient and just try to inch forward every day. The first job you get most likely won’t be your last, so keep an open mind and keep your eye on the prize.
Hope this helps. Good luck!