Need Database and Shopify Guru To Add Products To Collections In Bulk - Fix another freelancers mistake

I hired a freelancer to scrape and import products into our Shopify store. Instead of assigning the product categories and sub-categories to collections, he assigned them to tabs. Need an expert to fix this issue and assign products to the appropriate collections. This can be fixed in excel and re-imported. Either way be sure to state your plan in your bid or chat.

Need quick turnaround. Looking to establish long term relationship.