It can be converted depending on state law. It may not be widely practice or some radical gormen servant prohibits it, hence it was label as impossible.

For sabah, one of the easiest way to own a bumi lot is get a bumi (wife, relative, mother or father or proxy who is a bum) to own it for 5 years, then after a certain period of years holding it, it can be convert into non-bumi lots with state approval.