I have been at my job for 25 years. I work for a Derm. Dr. and help with surgeries and also cut slides at the cryostsat machine. I was trained on the job so I have no certificate or degree. Lately I was thinking about taking surg. Tech classes. My husband says that at 57 yrs. Old I would never get hired after the schooling or make what I am making now. What do you think? Good idea or bad!

Have you thought out why you want to change and switch careers? Could you be wanting to switch offices? It is a big step to take and depending on your financials could be a boost or a deal breaker. So, you need more information.
I would check with local medical training schools and see if any of my on the job training skills would translate into credits with testing and no classes. I would also see if I could find some surgical people to kind of test the waters and see if you could find out the avg salary range and the best employer. I would definitely get more info before I jumped. :) Good luck