I noticed that there is no download link for the Flash Builder 4.5 Eclipse plugin as it exists with version 4. It seems that a separate plugin installer is no longer necessary.
Here are the steps:
1. Install the standalone version.
2. Go to the program folder of Flash builder 4.5 (program files\Adobe\Adobe Flash Builder 4.5)
3. Then go to the folder "utilities" and execute "Adobe Flash Builder 4.5 Plug-in Utility"
4. Point the installer to your Eclipse folder
Next, next, OK, next, next, done!
