The sill wrap can be cut with a chopsaw using a fine tooth carbide blade, or you can use a hacksaw if necessary.

Notching can be accomplished with a jigsaw or, once again, you can use a hacksaw.

The two pictures below show the sill wrap piece being applied. The picture on the left shows how it fits on the wood window sill. The picture on the right shows the piece installed before the end caps are installed. Even the wood trim below the window sill gets covered using L-Angle trim.

The pictures below left show the end cap before being cut and installed. The cap is 6 inches long, and can do both ends of a sill. Notice the legs on the back. Sealant is applied to the legs to hold the cap in place. The picture below right shows the cap installed.

Here is the end result. Notice that the wood trim below the sill has been covered as well as the wood around the window.