Not that hard really , air forces are always disposing of scrap components including engines so it probably went out hidden in a truck load of scrap. It would have had to involve logistics and security and mid level officers , the brass wouldn't have known anything about it, the question is where would the engines go ? Probably to be sold BACK to the malaysian air force via one of their suppliers via 'friendlies' inside that could gloss over the fact these engines were already listed on the inventory , those engines are too hard to ship anywhere without attracting a lot of attention.