Change in quantities: From Case to Units

Hello forum, how are you all doing?

This is the situation. When we started with Netsuite and this company, we received the PO by the cartons, so logically we sell by the carton of course. Each carton has X amount of inner packs or boxes inside, and Y amount units in each inner box.

Now, new customers will rarely buy a whole carton of products, instead they would buy a few units or a inner box/pack in most cases. Also in our field, pricing  and costs are usually calculated by the unit.

So, we would like to change the current inventory from boxes/cases/cartons whatever terminology is preferred to single units; not being a Netsuite Guru, and just a user with enough knowledge for daily operations and the webpage end, I need some info on how to do this change.