How to create credit memo on over charged invoice?

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Hello,

We have an issue where we have a PO with qty for line 1-4 is 60 and unit price is $289.65 each and line 5 is with Freight amount of 300.

All the lines are received.

Now Supplier has sent the invoice for line 1 with Qty 60 but unit price as $389.65. Business has entered this invoice in the system, and the result of which there $6000 of IPV showing. Then Supplier sent two credit memos one with $5400 and one with $600.
Please suggest how we can create them in the system and attach to the invoice so that the IPV and can be reversed and actual amount can be hitting to the accounting.