Honestly easy stuff. It's like a window decal if you have ever applied one to your car. Clean the surface (alcohol), a quick fine sanding is a good idea, then apply the pinstriping by laying an inch or two extra that you will cut off not in the line you are wanting to stripe (to keep your starting end stuck to the surface), apply along the line you want keeping good tension and smoothing as you lay the striping down. When you reach the end of the line, smooth down a little extra to make sure you have a seamless integration if you are connecting, and then using a razor-blade cut off your extra ends.

I wish I could explain better, I can/will do a write-up when i paint two frames hopefully In mid-october. If you are clearcoating, keep in mind that laying the pin-striping down before or after clear coating will have an effect on the permanence of the striping (yes you can peel striping off)