I'm not following the feed here and confused how I should do this in my situation. 

We had an invoice for $129.65. When the check/payment came in, a sales receipt was created, and then later deposited along with other checks later. 

We realized today that the $129.65 was deposited without being linked to the invoice. 
What are the exact steps to link a portion of that deposit ($129.65 of $467.65) to it's appropriate invoice? 

Thank you for the specific process. 

Jason