Customer Payment more than Invoice

SUGGESTED

I have a sales invoice that is from several months ago.  There was a claim with the shipper which has since been resolved.  We received a payment paying the invoice in full PLUS paying for shipping fees.  The shipping fees were not on the invoice.  I need to offset the invoice 100% and then post the difference to freight.  How can I do this?  I'm new to Sage and was thinking it would be easy and could just edit the deposit adding a couple lines breaking out the freight but it appears it doesn't work that way?  Any help would be greatly appreciated.