Hi, if you've been out of touch with academia (for a long period) and want to get back to it (this is your case) some/most departments are happy to let you enroll into some postgraduate degrees (Diploma, MPhil, Msc, etc) and see how well you do. If you are successful, it may be possible to transfer to PhD (after a few months). The best thing to do is to consider a university, a supervisor and get in touch with them, directly.
Give it a shot !