Help with creating ADS(Aim Down Sight)

I tried to use @EgoMoose ’ s Aim Down Sight tutorial but I think his viewmodel is not built like mine. So I am trying to create a ADS system which is similar to this:

How my viewmodel is built:
image

The Aimpart is a part that I would use to attach it to my viewmodel’s rootpart

Any suggestions on how could I create such thing?