[Windows Phone 7 Q&A, Help & Troubleshooting] thesecondsfade:
K... this is a lot of steps but it's worth it, believe me. WP7 is much better than iPhone. Note, this is going to wipe all the contents off your phone but you'll be able to freely redownload any apps you bought already so don't worry about that.

The first thing to do is to put an older version of WP7 on your phone:

1. Download THIS ROM file.

2. Unzip the contents.

3. Turn off the phone.

4. Hold power button and volume down on the phone. It will enter the bootloader mode.

5. Plug the phone into your computer. Wait until the bootloader says "USB" on the bottom.

6. On your computer, launch ROMUpdateUtility (the one you downloaded on step 1).

7. Follow all the steps on the ROMUpdateUtility. This will probably take 10-15 minutes.

8. You now have an older version of WP7 on your phone.

9. Setup your phone as you did the first time you started it.

The next step is to Developer Unlock your phone:

1. Download ChevronWP7 (without sideload limit).

2. Unzip onto your computer.

3. I'm not sure if that zip includes the cert, so you can also download this certificate.

4. Email chevronwp7.cer to the email address of your phone.

5. On the phone, open the email.

6. Tap the attachment to download it to your phone. It turns into a shield.

7. Tap it again to install it.

8. Make sure the phone is plugged into the computer and make sure Zune is running. Wait until the phone is done syncing 100% with Zune.

9. On your PC, run ChevronWP7.exe

10. Click both checkboxes.

11. Click "Unlock", and viola... unlocked!

12. Download Tom XAP Installer. Unzip to your PC. Run the exe. It will automatically associate XAP files to Tom XAP Installer in Windows (XAP is the file type of WP7 programs). In the next steps, you'll just need to double click the XAP files to install them to your phone.

The next step is to make sure the phone doesn't automatically relock itself:

1. Make sure Zune is running, you are connected to your computer, and the phone is synced 100% with Zune.

2. Download TouchXplorer. Extract it to your PC. Double click 'TouchXplorer.xap' to install it on your phone.

3. Download HTC Connection Setup. Extract it to your PC. Double click 'Connection Setup.xap' to install it on your phone.

4. Download unlockit.zip. Extract it to your PC. Double click 'unlockit.xap' to install it on your phone.

5. On your phone, if XBMOD.Files.Deployer does not automatically run, go to your App list on the device and tap it to run it.

6. Now on your phone, run TouchXplorer.

7. Navigate to the directory \My Documents\My Ringtones\

8. Tap and hold the file CustClear.provxml, then tap 'Copy'.

9. Navigate back to the folder \Windows\

10. Tap the settings menu (the three dots in the bottom right corner), and select "Paste".

11. Go back to your App list on your phone and run HTC Connection Setup.

12. In HTC Connection Setup, hit the OK button (on the bottom with the check mark).

13. Now your phone will not automatically relock itself when you reconnect it to Zune.

You can now update to the latest verion of WP7 in Zune and it will remain developer unlocked for you to deploy homebrew apps, including custom ringtones, to your phone. To update WP7 in Zune, go to the Phone Settings, then to the Update tab. It takes about 40 minutes to complete the whole update process.

To install custom ringtones, use RingRing7. It automatically converts your MP3 files on your computer and places them in the phone's ringtone folder.

For a whole bunch of other homebrew apps, visit this thread. There is a ton of awesomeness there.

I wish this was more simple, and I can imagine that an average WP7 user would not want to do all of this just to get custom ringtones, but stick with the phone for a while. You're not going to regret buying the HD7. I have had a much better experience with it than I ever did with my iPhone or the many Android phones I have used.

Hope this helps!