I. Before You Begin
1. You MUST have done our How To Root the HTC Hero (Unrevoked Method) procedure before doing this one.
II. Loading a Custom ROM
1. If you have a GSM Hero head over to our HTC Hero ROMs
If you have a Sprint Hero, head over to the HTC Sprint Hero ROMs section
Choose a ROM you want to try (do NOT load a Sprint ROM on a GSM Hero or vice versa!). Download it and save it to your computer (do NOT extract it, leave it as a .zip)
2. Plug the phone in via USB cable and mount the sd card so we can transfer files to it.
3. Copy the ROM .zip file and save it to the root of the sd card (NOT in any folders just on the sd card itself). Once it is done copying, unplug the phone from the usb cable.
4. Turn off the phone, then turn it back on by holding down Volume Down and Power until the white bootloader screen comes up (if it finds the PC36IMG.zip on your sd because you didn’t delete it, just say NO when it asks you if you want to update). Now using the volume buttons select Fastboot, then select Recovery and wait for the phone to boot into recovery mode.
5. Scroll to Wipe Data, select wipe data/factory reset and then select wipe dalvik cache.
6. Now scroll to Apply .zip from sd card and select the ROM .zip file we saved to the sdcard and wait for it to finish flashing. Once it is done, hit reboot and you are all set! Enjoy! If you want to flash a different ROM, simply redo this procedure and choose a different ROM.