Hey guys I am going to be writing out step by step on what to do if you want to flash a custom rom. You need to be rooted if you need to know how to root your Evo 4g go here
How to Root Htc Evo 4g If you are more of a visual person then I will have a youtube video below where I go over all the steps and you can actually see what it should look like. 1.) Place the Rom that you want to flash on your Sd card. Do not put in any folders on your Sd card keep it in the zipped folder that it came with when you download it in. 2.) Place Virus's super wipe on your Sd card just like you did with the Rom make sure to not put in any folders just keep it in the folders that it is when you download it. You can find the Virus Super Wipe here
Virus Super-Wipe click here to download . 3.) Get an app called "Quick Boot". Go into the app and allow it SuperUser permissions. Click on the thing that says Recovery. 4.) After you boot into recovery go down to flash zip from Sd card. Your touchscreen will not work in Recovery so you have to use the volume rockers to move up and down and use the power button to select something. After you have gone down to flash zip form Sd card then install zip from Sd card. After that go down to where you put the Virus_SuperWipe file and select it with the power button. It will delete a bunch of files and it will completely wipe out your phone. Make sure to do a nandroid backup before you flash this SuperWipe. 5.) After this is done go back to flash zip form Sd card and go down to the rom that you put on your Sd card before and select it. After it is done you select reboot and then your phone will reboot into the new Rom. Thats it, it is that easy. Your phone will take A long time on the first boot to get into your phone because you just wiped all the data and it is a new rom so it will take a while don't be alarmed if it takes long. 6.) Enjoy your custom Rom. Hopefully These steps helped you. Enjoy