You can download optifine here: http://optifine.net/downloads once the file finishes installing run it with java. OptiFine only give capes to people who donate to them a minimum of 10 dollars. You can donate here: https://optifine.net/donate enter your minecraft login and then use the drop down selection to select banner and insert the the url. Then use the paymentwall to use a credit card. If you're still having trouble you can probably look it up on youtube. Also beware of the youtube videos that say "free optifine cape" they're just trying to steal your minecraft account.