Rear Frame Rail damage
 

I got rear ended and the bumper is screwed, but otherwise the Civic doesn't look too bad. However there is a crumple in the rear frame rail under the trunk. I've looked at the area and there appears to be a place where the frame rail is extended past the axle. It looks as if that part of the frame rail can actually be cut away and a replacement put in its place. It looks like it sort of nests in there... Considering the current condition of the trunk (which doesn't really worry me) and the frame rail, how could I go wrong by attempting to replace this section of the frame rail? Once this is repaired all of the cosmetic damage can be completed. Is this complete folly?