Many engineers have come to me asking for advice on how to get into marketing.  I first find out why they want to make the switch to the "Dark Side" and their expectations of the position.  If these engineers still want to transition into product management after I've provided them the gory details of what the role entails, my advice is for them to build their marketing skills and experience.

One option is to find positions, like technical marketing, that will allow engineers to build their marketing skills and experience.  

There can also be opportunities for these engineers to build skill sets in their current jobs.  Believe it or not, engineers can work with their managers to help them make the transition.  There are managers who are interested in developing their employees and are willing to share or lend their engineers as resources for product management.

Finding ways to build skill sets can be as easy as volunteering for marketing, business development, or like positions in social or professional organizations.

Also, joining a professional marketing organization like the Silicon Valley Product Management Association (SVPMA) will not only provide networking opportunities, but also educational opportunities in product management.

Another option for engineers looking to transition is to take product management classes from organizations such as Pragmatic Marketing or 280 Group. I have only taken courses from Pragmatic Marketing and believe these courses will help engineers learn new skills set as well as gain a better appreciation for the product management profession.

If you're an engineer looking to transition to product management, there isn't a simple "how-to", but there are many paths available to you in getting there.  Build your skill sets and keep your eye on the goal.