Happened to me over the last week.... left rear door froze shut. I tried to pull open and something popped and rattled down inside. I dissassembled the door and used JBWeld to put it back together .... twice. Second time I dremmeled out a channel in the center of the broken hook-shapped piece and set in a bit of sheet metal. It didn't matter. Still broke at the glued part. So, I've just ordered a replacement handle from subarupartsonline. We'll see how it works out.
Seriously, why would Subaru make a critical part like this out of plastic. Imagine someone being stranded in their car after a wreck with the door slightly jammbed because of frame twisting. Instead of being able to yank the door open, the handle breaks off. Jeesh.
OTOH, the directions in the thread above were perfect. It is somewhat difficult to get the lower two tabs out of the door, but eventually they will work out with some slight grunting and cursing.