Headlight lens replacement 89-92

[fairlaniac]

My headlight lenses on my '89 are fogged on the outside and the inside due to a crack. So I picked up some nice clear, crack free headlight assemblies. The black plastic housing (bucket) they fasten to is broken so I've taken one lens off the "bucket" to put on my truck. Of the three plastic winged looking nuts I broke two. How do you remove these without breaking them? I tried to gingerly remove them but didn't work. I don't want to break the ones on the truck currently so I can reuse them. It appears the "winged" portion is split and the piece against the bucket has two nubs that look to retain the "wing". It looks as if you could pry the lower part of the "wing" up they would turn easier and prevent breakage? Any hints or advice is appreciated.

Thanks,