How to Disconnect a Jumper

Stupid question. I brought that Arduino Motor Shield R3 want to use external power (12V). Therefore I need to "disconnect" the jumper from the back of the shield. But how do I do that? Do I need to solder that? I read somebody scraped it out. Is this the way?

You use a sharp knife and cut away the small track. You put a solder blob on it to connect it back.