How do I get data from my survelliance onto a usb?

I caught my neighbor vandalizing my property. I want to know how I can get the footage off of my video surveillance DVR and put onto a DVD or more preferably a USB. I need it for evidence. The video footage I need is only a few minutes long but I have the DVR on continuous record because he's crazy. Please help....I need this for court tomorrow and I need play by play instructions. I have the Security First digital surveillance system. The DVR is a triplex Network DVR.