I passed the 2010 HKMLE parts 1 and 3 in one attempt. It was not easy, but it can be done. I was preparing for a year before the exam, as it was nearly 20 years since I had done any Medicine, OB/GYN or Surgery reviews (I am a pediatrician, US-trained).
Part 3, the clinical exam, is much harder and is much more about pleasing examiners. You should begin preparation for part 3 long before you take part 1. Part one review is practically pointless, since it empasses virtually all premedical and medical basic science. If you werent asleep for those 4 years, you will likely remember a few things, probably enough to get you through part 1. Part 3 should be prepared for as for the MRCP PACES exam, but with the same depth in OBGYN, surgery and peds as in medicine. It is not true that the HKMLE is about "Hong Kong diseases"- you need to only know a little more about the higher prevalence diseases there (nasopharyngeal carcinoma, hepatitis E, tuberculosis, mitral rheumatic heart disease) than for the MRCP or USMLE.
Anyone who is interested in finding out more should see the HKMLE page on Facebook or email me- Im happy to share review materials.