Welcome - @Rubenhil24 You can cancel promote plus trial by going to your active subscriptions.
How to cancel an App Store subscription on iPhone or iPad
Follow these steps to cancel a subscription on your Android device:
Your Promote Plus benefits will continue until the end of your current billing period. Then your monthly payments will stop, and if you have a Promote Plus promotion running, it will end. You can still re-subscribe at any time, or buy individual, limited-time promotions for any items you’re selling.
I have a iPad 2 that my sister wants. The same settings let me change owners from me to my sister. Just had to remove it from my account. Then reset the iPad. Not what you were talking about I think but it led me in the right direction. Thank you.