Find your logo file, click on it, and you can start placing it. The logo will be surrounded by a box and various handles that will make its placement faster and easier. A good idea is to change the blending mode to Darker, as the background disappears and you have only the necessary grey and black areas.
In case you want to change the color, you would need to add an Invert layer (go to Layer/New Adjustment Layer/Invert) and here you can add the Invert layer on the logo Layer, hold ALT and then click the line that appears between the layers. You have to select the logo layer and then modify the blend mode to make it Lighten. This makes it easier for you to see the logo if you whiten it up properly!