Getting my gun into NZ

Anyway i want to buy a mp5a5 off eHobby Asia, has anyone done this? bought a gun off them. How do i get them to disable the fully automatic part is it? so it can get past nz customs with np problems, anyone know? i figured a email...but when i emailed them last time bout my stuff, they replied with words barely english D=
Cheeeeeeers
see yas soon