That's great! It's good that it pops without removing the sides, as I managed to remove the right trim of the right seat, but this doesn't help removing the back, in the pics you can see how it's fixed, the circled clip is the one that will break...

It's a pity a clip broke but your pics of the fastenings are very useful for future reference.

As my confidence grew, I carefully unclipped the left trim of the driver’s seat (in my car). To my surprise, nestled within was the belt pretensioner—a feature absent from the passenger seat!? Even better, this time the clip remained intact!