What is a one-sentence summary of the following article?
Click the magnifying glass icon in the top-right corner of the screen. In order to allow all software installations, you'll first need to restore an installation option that MacOS Sierra got rid of. It should appear directly below the Spotlight search bar. This is the code that enables the installation option. This is the password you use to sign into your Mac. Doing so will restore the option you need in the Security & Privacy menu. Click the Apple logo in the top-left corner of the screen. A drop-down menu will appear. This option is near the top of the drop-down menu. It's near the top of the System Preferences window. It's in the bottom-left corner of the window. You should now be able to edit the settings in this menu. It's below the "Allow apps downloaded from" heading near the bottom of the window. Doing so prompts a pop-up window. Doing this will allow you to install software from unsigned developers without having to confirm from within this menu.  If you don't install any unsigned software within 30 days, you'll have to re-enable this settings. Click the lock icon if you'd like to prevent further changes. You should now be able to install your software as you usually would.

Summary:
Open Spotlight . Type in terminal, then click  Terminal. Type sudo spctl --master-disable into Terminal and press ⏎ Return. Enter your password. Open the Apple menu . Click System Preferences. Click Security & Privacy. Click the lock icon. Enter your password, then click Unlock. Check the Anywhere box. Click Allow From Anywhere when prompted. Install your software.