Is Wrong idea to change scale inside the UE4 becouse if you after want to make our use assets from our for marketplace your wrong scale generate problems for you our your clients.
I suggest to change your setting in your 3D modelling software
Here tutorial to change scale in maya and maya lt: UE4/Maya: Set Up Grid in MayaLT/Maya to Match Unreal Engine 4 - YouTube
Here for 3ds max - YouTube
If you need this rescale to other 3D software you found all in youtoube tutorials by searching
Name of Software + to UE4 Scale