Product review (5 stars): Works as expected with a bit of effort
I wanted only the left side (which was broken) but I had to buy both - since this came in as a pair. The installation was a bit more tough than I anticipated.
 When I was chatting on the Samsung support line, they said they don't sell this directly since it is a 'technican-installable-part' (v/s self repair). I found that a bit strange since it appeared definitely do-able (with a bit of elbow-grease as almost in all cases). In any case, the parts arrived, I took out the broken piece from the rack and spent about 10 mins on putting the new one in. I had to look at exactly how the right one was setup to do the same on the left side (even though it appears intuitive, it was a bit of a struggle).
End result - part installed, rack is no longer sagging!
I hope if and when the right side breaks, I will find the one where I put it away :-)