Replacing front door-how to move door entry alarm- Accenta G3 model?

I have just ordered a new front door (upvc) and will need to move existing Accenta G3 front door sensor. However the door surveyor stated I would need to do this myself which I'm nervous about doing. Is it just a case of unscrewing the 2 halves (1 on frame, 1 on door) and then rescrewing back into the new door or is it more complicated- ie disable alarm (how?) anything else I need to know pls? Thx