Efficient Way to split up strings?

So I have a data problem. We're in the process of getting a badly needed new ERP system. This means we're trying to transfer over a lot of data and one of those lists we need is customer's parts and what their agreed pricing is.

I have a list of my company's part numbers and what our customer's call those part numbers as well as our agreed on price. For some reason, someone decided that when a customer changes their part number or comes up with a new part number for our part, we'll just add a '/' followed up with the new part number in the same field. This results in a list looking like attached where we have any number of customer part numbers all in one cell on one line with one company part number. We want to discontinue this and need to convert the current list into just one part number per line.

The issue is this will be very time-consuming to do manually because there could be one of our part number but 4 customer part numbers all in 1 line and I need to convert that into 4 lines of data basically repeating the same info and this is the situation for thousands of part numbers.

Is there any automated way to break the customer part numbers out separately(they're all separated by '/') so that they're line by line and then I can just do a lookup on the old list to bring in our part number and pricing info?

Thanks for any help.