3 ways: 1.) Reset the PC inside Windows settings 2.) Press F9 during boot to run the recovery manager 3.) Create an installation USB drive using the Microsoft media creation tool
Don't forget to back up your computer before resetting. Personally,i think it's not easy to install Windows 10 using the Microsoft Media Creation Tool,i wasted 6 hours on this without success. There are the easiest ways for me to install Windows 10 on computer. https://www.wikihow.com/Clean-Install-Windows-10 If you are going to download Windows iso,the download link of Windows iso can be found from Microsoft and Google.
It's quite straight forward and shouldn't take more than 30 minutes to complete if you format all the existing partitions and do a fresh installation?