Yeah, if you don't have much building experience, that "connect the Reset Switch ... " thing won't help much. But I can explain.
On the front of your case one of the pushbuttons is "Reset". Its normal use is to let you force a reset when your system freezes. The case makers want you to change the wires from that switch so that it becomes your fan speed selector pushbutton instead. How?
Shut down your system, disconnect the power cord on the back, and open the case side panel. Check this photo of your mobo
https://i.ebayimg.com/images/g/eZIAAMXQTgZQ91tf/s-l640.jpg
NOTE that this photo shows the board with its REAR edge (with the rear panel connectors) at the bottom. But inside your case that would be to the LEFT. So imagine that photo rotated clockwise a quarter turn, with the rear connector panel at the upper left, and the blue and black RAM slots vertical and to the right of the main CPU chip position. That's how it will look inside your case. Now, look then at the front edge of your mobo very close to the bottom corner. There is a header called the Front Panel header with several different colours of pins on it. Slipped onto those pins will be several diferent wire sets, each with little connector sleeves on the wire ends, and HOPEFULLY there will be labels on those connectors. You are looking for a pair of wires labelled RESET. They may be two wires in one 2-hole connector, or they may be single connectors on the ends of two wires. Either way, THOSE are the two wires you should disconnect from this header and plug into the pins on the end of your case's fan BOX unit. In this case do not worry about connector polarity. The front panel Reset pushbutton is only a momentary-contact switch just like a doorbell button, and + and - do NOT matter. When done, close up your case, reconnect its power cord, and boot up. From now on you can use that front panel RESET pushbutton to change the speeds of your fans.
Now, this means you no longer have a Reset button to deal with freeze-ups. But there's another way when you need it. Push in and hold the regular "On / Off" button for at least five seconds to force it to shut down immediately. Release the button for a few seconds. Then do a normal push-and-release of that same button to start up again.