How do you change permissions of a specific folder?

A.
Control-click the folder and then click Change Permissions.

B.
In Finder, select the folder, then choose Get Info from the File menu. Change permission in the
Sharing & Permissions pane.

C.
In System Preferences, click the Sharing pane. Locate the file in the Shared folders section. Click
Change Permissions.

D.
Open Disk Utility, then drag the folder into the sidebar. Change permissions in the resulting
window.

Explanation:

https://support.apple.com/kb/PH6732?locale=en_US