From the RegawMOD development page:
What it does:
- Verifies Device and Battery Level (Needs to be charged to at least 40% before running)
- Reboots to Bootloader and Gets Unlock Token
- Sends Token to HTCdev.com
- Retrieves Unlock_code.bin
- Unlocks Bootloader
- Flashes TWRP Recovery
- Sends Superuser packages and busybox to device
You’ll need a Windows computer, the HTC drivers, and .NET 4.0 installed. Links to the drivers and .NET 4 are on the development page if you don’t have them already.
They’ve produced a great walkthrough video of the app rooting an HTC EVO 4G LTE if you’d like to see it in action before freeing your phone from its shackles.
An important thing to remember is that you need to clear your Google Wallet settings before you do this because, if you don’t, you might lose the Wallet/secure capabilities of your phone forever.