As Gordon Bennett says, with that time and an ATPL already (I believe you also have to have a current type rating) you are exempt from the study, but still require sign off from an ATO to say you're good to sit the exams.
There are many in The UK - Bristol Groundschool, CATS to name a couple. I'm sure there are more in Belgium as well. Give Noush a call at Bristol Groundschool for chapter and verse.