Morrison (aka @moestepp) let me know that he has put together a video guide with instructions on how to install hybrid or beta OS versions using BlackBerry Desktop Software for Mac.

I’ve transcribed the steps (below) for those that prefer text, but the video is better since it offers visual aide. The BlackBerry used for this tutorial is a Curve 8310 on AT&T. Do this at your own risk and only if you are comfortable with using beta/leaked software.

Morrison has also provided links to beta OS files in DMG format for use with a Mac computer. This method is mainly used for a hybrid OS upgrade. If you are using a beta “you would typically include the radio file in the same folder” (according to Morrison).

• 8330 5.0.0.230 http://www.megaupload.com/?d=G4VGQBM9
  
• 8900 5.0.0.238 http://www.megaupload.com/?d=V0IQRULX
  
• 9000 5.0.0.238 http://www.megaupload.com/?d=S3CMOBM2
  
• 9530 5.0.0.230 http://www.megaupload.com/?d=PL31VO1W
  
• 9630 5.0.0.230 http://www.megaupload.com/?d=G1PURKUJ

Here are the steps for use with a hybrid:

1. Plug your BlackBerry into your MacBook with BlackBerry Desktop Manager running
2. Install the carrier recommended OS (in this case AT&T OS 4.5.0.110)
3. Reload the OS that the carrier recommended for the phone. This will download all the appropriate files that are required.
4. Have the hybrid OS handy (in this case 8330 OS 5.0.0.238)
5. Go to Hard Drive > Username > Library > Application Support > BlackBerry Desktop Manager > Device Applications > Folder with numbers and letters
6. Open the Java file containing the hybrid OS files
7. Select all the files in the hybrid OS folder
8. Drag and drop these files into the folder with numbers and letters found in step 5
9. When prompted to replace files, click on apply to all and then replace
10. Go to BlackBerry Desktop Manager (should be running in background) and click on Applications and click Check for Updates
11. It will say there are no new updates in the next screen. Click on Show Other Versions in this screen.
12. You will now find the carrier recommended OS that was installed in steps 2 and 3. Click on the radio button to the left so it is “selected” and then click on Select.
13. Click on Reload
14. You’re done!

The Desktop Manager for Mac will think it’s just reloading the current OS to the BlackBerry but since you copied over the files from the hybrid OS it will actually be loading a different OS. As always please make backups before attempting to install or upgrade anything.

If you decide to try this out let me know how it works for you in the comments!