HighSierra to BigSur I am stuck

[jb3nny]

I am confused ...

I have macbook pro 2010
fresh install up to date of High Sierra. I want to install Big Sur as it supported by MS Office 365.
I have usb 64GB formatted as per instructions
I have Big Sur dmg and the Micropatcher downloaded. (zip file from this site)
In the directions I am supposed to put the Installer for bigSur.app in the applications folder. But I am lost as to where I get this from? So that I can complete the terminal commands to create the usb patcher.

Please help
JB