Okay well first you need to download it. Then upload the picture to the program you use (like paint, photoshop, gimp, etc.) and then draw your answers. Or you can draw the pictures by hand and if you have a scanner you can scan your pictures on to your program and use that. I'm sorry that I am being vague but I hope this kinda helps.
It's ok. All you have to do it download it, put it on paint or whatever program you use, draw on it, then post it back up on deviant art. That's my best to explain the process. Sorry if my explination is vague.