(Click to enlarge)

As you can see they are adjustable

You can see here it will rotate to these two positions

After you get the slider ON and in position....take a marker and set it next to the slider

Then set the fairing against the slider/marker and trace the slider outline
 
 

Use a hole saw 1/8" larger I.D. than the O.D. of the slider and pop that hole out

 
 

 IShould look pretty good when complete. And remember the slider is adjustable so move it to help you