Update 2: Here's a direct download link from our own (fast) mirror for the EVO 4G Official Gingerbread OTA.
To flash it, follow these instructions:
- Download the OTA
- Rename the file "update.zip" (the actual file suffix needs to be .zip, make sure .zip isn't just in the name [eg, not update.zip.zip])
- Place the file on the root of your SD card (the main directory you see when you mount your EVO as a disk drive)
- Reboot into recovery (power off, then hold volume down when you hit then power button to power back on)
- Select recovery from the menu with the power button, then, when the sign with the exclamation point appears, press Power+Volume Up at the same time, and wait (up to 30 seconds).