OLD Laptop given as a gift; HOW CAN I REMOVE PREV. OWNER'S APPLE ID?

Hi,

I need help.

I have been given an old macbook air laptop and have created my own apple id and icloud etc.

The thing is, there was a time when it got locked and asked for a 4 digit pin.

I had to contact the previous owner to get it unlocked.

What I want to know is:

• is there a way I can check the prev. owner has already removed my device from his/her apple device list?
• is there a way I can remove my device and troubleeshoot things from my end so I dont have to ask again the previous owner to provide me a pin next time it gets locked again?

Please I need help regarding this one.

The previous owner and I dont talk much and I dont want to be bothering them all the time regarding the pin next time I encounter it. Also, it is such a burden when it gets locked suddenly while im using my device.

I dont really know why it happens or what's wrong but it's so not cool .

I need help, all suggestions are welcome.

Thanks