Left hand corner near the top you'll see a socket. It'll be right behind the stuff that sticks out the I/O shield. On some mobo's it's a square 4 pin socket, on some higher end mobo's it's a rectangular 8pin socket. The connectors are usually labeled EPS. The 2x 4pins have a tab that joins them together if you need them as 8pin, or there's 1 specific 4pin that'll fit a 4pin socket, the other is unused. You need to check the socket and look at how it is keyed, which pin is square, which pin is D, and line them up with the corresponding 4pin connector. Just remember that power supplies are designed to be universal, so you will have extra connections that you will not use.