CRM re-build.

CRM re-build.

Good morning guys, 
I hope you're going very good.

We are a company that have been used ZOHO CRM  for 3 years now. It was not built properly, all the employees had access to everything. 

As an example, a product's name  is "Billoboards_masterhead", and all the commercial agents use it, but if there's a new recruit, the new commercial agents creates a new product "billboards" and so on.

So we have been stuck with so many names of the same products, so many names of the same company etc etc.

this is getting our data being ruined and everything. My question is how to regroup all the products in one single new clean product ( knowing that they're connected to other modules such as orders, activities... I would be grateful If you gave me an answer.

Thanks!