engineering to medicine pre-req advice

I am a 29 year old finishing up my PhD in electrical engineering while working. I am contemplating a career change to medicine and wondering what would be the best approach to taking pre-reqs. I started my undergrad at a local community college and took a lot of pre-med courses in 1997-1999 with a 4.0 GPA. I wasn’t sure about a career in medicine at the time and I ended up going the engineering route. My undergraduate GPA out of engineering at the 4year university was a 3.9 in 2001. The only pre-req I hadn’t taken was Bio II. I’m not sure if I should retake all the chemistry bio and physics courses again since they were at a community college and 10 years ago. Would it be wise to just take some upper level classes like biochem, microbiology etc. instead.

Also if there is anyone else out there switching careers what did you do for clinical experience?

I would appreciate any advice.