The above link takes you to the most upto date version. Click on download and save to your desk top or a location where you can find the file again.
Once the download has been completed, double click and follow the instructions on line. Make sure that you uncheck the box that asks if you want to make Firefox your default browser. Import your IE favourites, passwords etc and choose the option to import your IE home page. You will see the Firefox logo on your desktop so you are almost ready to go.
You do need to download flash player first before using Firefox as this is the help app that allows you to see the graphs and charts. Download again onto your desktop – it does tend to be very quick. Double click on the install flash player logo and follow any online prompts however it should just install.
You now have Firefox set up to view Google Analytics and it will show you all the charts and graphs that are available to you.