lari258 (Author)
Likely course of action would be to re-sell the MacBook to private buyer
and have it ready ahead of time through use of Support instructions.
Also resellers with retail business with Apple may offer better trades
in person; if you don't like their offer, just walk away.
What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
//support.apple.com › en-us › 102773
Erase your Mac and reset it to factory settings - Apple Support
//support.apple.com/en-us/102664
"If you're selling, giving away, or trading-in your Mac and want to leave it
in an out-of-box state, don't use the setup assistant or your previously
connected Bluetooth devices, if any. Just press & hold the power button
on your Mac until it turns off."
