I have a Half Dome 2 plus tent.  I think it's the 2010 model but I bought it used from a boy scout troop that was finished with it.  It is in great shape BUT it leaked on my last campout.  It didn't seem to be just the seams - it overall soaked through from the fly.

I am prepared to seam seal the tent since I know that's a normal thing to do.  However, I don't know where to start since it seems like the whole fly has a damaged waterproof coating.

Suggestions would be appreciated.