I'd guess you prepare the bottle in the same way you do when make a brass monkey (malt liquor and orange juice), that is chug it to the top of the label then add your juice.
When the word was Thunderbird
And the price was forty twice
Drinking wine and loving you was fun
Our love turned out to be a passing thing
Different bird of a different wing
Some damn fool put a dollar twenty nine
On a jug of Thunderbird wine