Extract the zip file and use the file flashplayer_10_3r183_90_mac_intel.dmg to install Flash Player on OS X 10.5.8. If you have further questions, please let me know. If you still have concerns, please do not negatively rate my answer, simply reply back before rating. How to Uninstall Adobe Flash Player on Mac. Adobe has created a dedicated uninstaller for Macs, and you can download it here. Launch the downloaded uninstaller like you would any other Mac application. Click on the Uninstall option. On PPC/Intel 10.4 10.5 Download PSD2FLA Introducing PSD2FLA - the Photoshop to Flash converter. Adobe Flash Player 12.0.0.70 installed with Internet Explorer 11 will automatically be updated to the Flash Player Update Mac 10.5.8 version.I have read this is due to the program being compiled in 10.6 or later.

Adobe Flash Player for Mac lets you access Flash content in Web sites when using browsers like OS X's Safari. The plug-in integrates seamlessly and through a preference pane, gives you control over the type of access each Web site has to your system. The only downside to using it is that it suffers from performance issues.
Pros
Configurable: The plug-in adds a new preference pane in System Preferences where you will be able to adjust your local storage, camera, mic and peer-assisted networking settings to either allow the feature for all Web sites, on a per-request basis, or to deny all requests.
Per-site settings: All the features listed above support per-site settings for even more precise control.
Advanced options: The app lets you delete all Flash-related data and settings as well as audio and video license files, deauthorize the computer, and access trusted locations for developer testing.
Cons
Get Adobe Flash Player For Chrome
Performance issues: Despite its long history with OS X, this software tends to slow down your computer and drain your battery.
Bottom Line
Adobe Flash Player Mac Os X
If you're constantly visiting Flash-based Web sites, you will have to install either this plug-in, or a browser like Google Chrome, which has built-in Flash support. Generally, the better way to go would be to use Chrome since there will be a lower performance impact on your system. But if Chrome is not your kind of browser, then this plug-in remains a viable solution for enjoying Flash content on your Mac.