This tutorial will take you through the steps for installing Firefox as an alternate web browser. Firefox is a great web browser, and it's always a good idea to have two web browsers on your computer. This way, if you ever experience problems with a website in one browser, you can switch to the other to see if the problem resolves itself.
Step 1. Begin by clicking on the following link: http://www.getfirefox.com/
Step 2. Click the green “Download now” button to begin your download.
Step 3. Once Firefox finished downloading, open your downloads folder and click on the Firefox .dmg file.
Step 4. Click and drag the Firefox icon into the Applications folder icon.
Step 5. You may be prompted to enter your computer username and password. Enter your credentials and click “okay.”
Step 6. Once Firefox finishes copying over, you can open Firefox from your Applications folder.