Hello LannWaldrop,
Since a Microsoft account was used to setup the computer and belongs to the person that has departed from your organization, we'll have to go with the Factory Reset option.
On the Lenovo G50 series of laptops, there should be a Lenovo OneKey button right next to the port where you would plug the AC adapter into the computer. You will most likely need a small item that can depress the button. Before starting this process, please make sure that the computer is turned off and connected to the AC adapter as this process may take some time.
Once the computer is off, depress the Lenovo OneKey button which will turn your computer on. Shortly after the computer has turned on, you will be presented with a "Novo Button Menu" with about four options displayed. Use your arrow keys to move down to the "System Recovery" option and press the Enter key.
Please follow the on screen prompts to start the Recovery process.