Replace/install a new outer duct. Is it really that easy
 

I'm a 73-year-old female, I'm not a mechanic, but I'm handy I need to replace this thing because it's not existent. And my battery keeps getting hot enough to have to be replaced blah blah blah. I was given the car like this and didn't know any better. So I can find these things, and it looks like it just snaps on the rounded rectangular thing that sticks out of the engine a little below to the right and in front of the battery. Can anyone help me? Thank you