I had a similar situation on the same Premier model when the rear bumper section bottommed going over a high gutter. The guard clipped back in quite easily, however the bottom clip was broken. Repairer wanted to pull the whole guard off and replace clip. In the end I got a small thin 1cm square right angled metal bracket from Bunnings which conveniantly had holes drilled in each side, glued it to the guard, held it in place with gaffa tape, let the glue fully dry overnight, and then screwed the remaining side of the bracket it back into the hole where broken clip was mounted. It has been like this now for over 12 months and never moved. Virtually a few cents for the bracket. If I remember correctly I used a pair of tin snips to round off the edges of the bracket where it screwed back on the original mounting position.