Installing mongo shell in OSX

I want to install MongoDB Shell in OSX intel based
as I go through the step,The 2nd one which is to Add<your mongosh’s download directory>/bin to your $PATH variable
I am not sure what to do next or how set PATH variable
Thanks in Advance

PATH is a system variable
You need to add mongodb/bin to this
You have to edit /etc/paths
Try sudo nano /etc/paths
add the entry and save the file

Please refer to OSX documentation