Class 31 snowplough fitting...

[Michanglais]

I'm trying to fit the provided snowploughs to a recently bought (new) Class 31. However, I'm not finding the instructions very clear - two arrows leading from the snowplough in the direction of the bufferbeam but, to what, I can't tell. I've looked on the model and can easily see the holes for brake pipes, etc. but I'm wondering whether I have to remove the bodyshell to get to the snowplough holes?