change correctly the COGS for A/P Invoice error (after A/R Invoice registration)

Hi,

I inserted in SAP an A/P Invoice with these items:

Item 1 - Inventory item - Line total 1000

Item 2 - Inventory item - Line total 100

Item 3 - No inventory item - Line Total 10

Then I registered an A/R Invoice with the same items:

Item 1 - Inventory item - Line total 1500

Item 2 - Inventory item - Line total 150

Item 3 - No inventory item - Line Total 30

For the inventory items the warehouse is 0 after the A/R Invoice.

Now I see that I registered the A/P Invoice with an error. The first line is not 1000, but 1100.

How can I change the line total, moving correctly all accounts?

I thought to do before the A/P Credit memo (in the same date of the A/P Invoice wrong) and then the new correct A/P Invoice with the same date.

In the following order to avoid the inventory under 0.

But this solution have problems for the cogs account, because all inventory items with the credit memo move only the inventory account.

What can I do?

Help me .

Thanks.