How to Install Android 2.3 Gingerbread on HTC Droid Eris: Complete Upgrade Guide
1. Download the Android 2.3 Gingerbread ROM for the HTC Droid Eris.
I would recommend the Kaos Gingerbread ROM v6. You can download it here.
Download Kaos Gingerbread v6 Android 2.3 Gingerbread ROM for HTC Droid Eris.
2. Connect your phone to your PC, or use a memory card reader to copy the Android 2.3 ROM to your SD card. Insert the SD card back into your phone.
3. Download the ROM Manager application from Android Market (Clockworkmod ROM Manager) and install it. ROM Manager will help you install, back up and restore ROMs easily.
4. Start ROM Manager and select the Flash Clockwork Mod Recovery option to install the recovery image which you will need if things go wrong. Also select the Backup Current ROM option to take a backup of your current ROM and save it on your device.
5. Now click on Install ROM from SD Card to install the Android 2.3 Gingerbread Kaos v6 ROM. Select the Wipe Data and Cache option before you start the ROM flashing.
In a few minutes, your phone should reboot and it will be running Android 2.3 Gingerbread.
If you have any problems with ROM Manager, just boot into the recovery mode manually and install the Android 2.3 ROM directly.
Also note, that you should have root access on your HTC Droid Eris in order to flash ROMs using ROM Manager.
Android 2.3 for HTC Droid Eris ROM Source: XDA
In case you have any doubts or any issues, comment here or leave a comment on the Kaos Gingerbread thread at XDA.