Unroot Samsung Galaxy Tab Active2 previously used in a company

I was recently given Samsung Galaxy Tab Active2 by a friend, who said it was given to him by his job. When he left, the boss said he could keep the tablet as it was an older model. The tablet is rooted in the company software, and his credentials were disabled, so I can't log in. The software automatically starts up as soon as it is turned on, and I'm unable to access Android settings as the software has disabled that. However, I'm able to get into recovery mode. How would I remove the rooted software and revert it to a normal Android tablet for everyday use?