How do I renew my ability to fly after 40 years?
Much has changed in 40 years, including airspace designations, ATC communications, and new regs.  If I were you I would take an online Private Pilot Ground School to learn about all the new changes.  These courses are not too expensive and it well worth the money.  

The AOPA does have a Rusty Pilot Seminar as well (link). 

Also it might be worthwhile just to sit in the passenger seat of a plane for a while to re-familiarize yourself with how it all works.