I am afraid you will have to pass through ground school again. Malaysian licenses are based on the UK systems and FAA licences are considered too weak to be recognised. You can contact MFA (Malaysian Flying Academy) (
[email protected]) (606 317 4026 ) they must be able to give you the details of what you need and can provide an assistance.
In the best of case at least "LAW"exams must be attended.
Regards