[GNC] Manually edit pmt info (reverse a payment) for a vendor?

[Eric Chapman]

I'm just getting started entering in 2022 data. I made some mistakes in 
using Accounts Payable and Credit Cards. The amounts in those accounts 
are accurate, but only because I deleted erroneously posted 
transactions. However, I have two vendors which show "prepayment" 
amounts when I do a vendor report.

Is there a way to manually change that data?

Since I only have one transaction entered for each of those vendors, and 
I'm just getting started, I would not be opposed to just deleting those 
vendors and their associated bills (invoices) and starting over (now 
that I better understand how AP and Credit Cards work. Is it possible to 
delete all transactions related to a vendor and then delete the vendor? How?

Or maybe I could somehow enter in a "debit memo" for the vendor (i.e., 
another bill) that would zero out the amount now listed as prepayment. 
But then how would I "pay" it such that the prepayment is applied to it?

Thank you for helping me correct my newbie errors!

-- 
Eric Chapman
GnuCash 4.13 on MacOS 13.1 Ventura running on 2018 Mac Mini (3.2 GHz 6-Core Intel Core i7)