Advice on Accord Rear Lip

I recently bought a 94-95 rear lip for my DA (a 90-91 to be exact). I dont quite get how to get it to attach to the rear bumper. I’ve seen other posts saying it’s only doable with 92-93 rear bumpers. but I’ve seen 90-91s with it as well. I haven’t seen much coverage on this topic (not recent ones with pictures at least). Looking for advice. Thank you!