As i understand it, if you already have an ICAO CPL - you are not required to do the full flying triaining course - you just need training 'as required' to take the skills test. However, the tricky bit is that you have to have passed either ATPL knowledge tests or CPL knowledge tests (almost everyone does ATPL level, so you'd not be doing yourself any favours doing CPL level)
This requires taking a full groundschool course with an FTO either full or part time (6-12 months)
Of course, if you've got an ICAO ATP, you dont need to do that part - you can just sit the exams, take a few rides with an Instructor and take your skills test.
It's in LASORS