Lucky you! Since you used Procedure #2 to root, you already have Clockwork installed.
Power off phone>hold volume down+camera+power>a screen with green lettering will come up>welcome to Clockwork
(if a screen with blue text comes up try selecting install update.zip to take you to the screen with green text). In Clockwork, use the volume buttons to navigate, and the camera button to select.
To install a ROM:
1) Put the zip file of the ROM on your SD card
2) Boot into Clockwork, go to "backup and restore" and then "Restore" (now you have a backup of your phone just in case).
3) Go to and execute "wipe data/factory reset". Then go to and execute "wipe cache partition".
4) Go to "install zip from SD card" then to "choose zip from SD card", find the zip of your ROM and select and install it.
5) Reboot and done!