1. Select the object in your scene that you want to apply the shader to. I'm using a simple scene with a sphere for this example. To select it go to the Scene tab and click on the object name so that it is highlighted:
2. Now go to the Surfaces Tab. Under the 'Editor' section you will see the name of the selected object listed. click on this so that it is highlighted:
3. Now go to the Contents Library and browse to the folder containing the presets - so for my example I need to find Shader>Presets>Eva1>Wood.
4. Double click on the shader image you wish to apply to your object, and you will see it appear on it:
You may wish to apply a shader preset to just part of a prop which has it's own texture. This is also easy to do, following the similar steps as above. Select the prop in your scene or just the part you want to apply the shader to. For this example I'm using a wooden chest prop which has separate object parts for the handles, base stand and wood box. I'm selecting the box part:
Go to the Surfaces tab and this time click on the little arrow beneath the prop name to see the list of different surfaces that belong to the prop. So in my example there are two surfaces for the box, metal and wood. So I'm going to select the wood surface to change the texture:
Now go to the Contents Library and browse the the shader preset, double click the one you want to apply and voila it'll be applied to the object surface:
I hope this tutorial has been useful. Have fun applying your shaders!