To quote for a Bark you've already responded to make sure you are in the 'My Responses' tab. From here select the conversation you'd like to quote for and click 'view.'
In the top left of the screen, you'll see the quote that you have provided for them. To edit this just click 'Edit' and make your updates on the screen that follows. The customer will be a sent an email when you make any updates to your quote.