Hey, this tutorial will teach you how to get the 'manual setup file' for Adobe Flash Player without downloading/using their default download manager.
What you'll need:
- A Computer with Microsoft Windows as it's OS (operating system)
- Functioning Mouse and Keyboard
Steps:
1. Go to their troubleshooting page which can be found by clicking HERE
2. Click "Troubleshoot Flash Player installation | Windows"
3. Press4. Type(or copy and paste) the following in the search box/bar and press enter Code:
Download Flash Player with the manual installer
5. Choose your appropriate Flash download. Most likely to be 'Flash Player 10 Plugin (All other Windows browsers, such as Firefox or Google Chrome)'
Have fun!
-NCU 
Edit:
Method2:
Go here: http://www.filehippo.com/download_flashplayer_firefox/
Credits go to LizardMan for method 2