Dfu mode? Or recovery mode? If you are just looking to reset the iPad to factory settings then Recovery mode is nearly always sufficient. The way I do it is to power off the iPad. Press and hold the home button. Keep holding the home button and plug a USB cable connected to a computer into the charge port. Don't release the home button until you see the Apple logo.
It's possible that the iPad may be activation locked so resetting it may not make it usable for you. But this is a good start.