are available on e bay, very reasonably, we are installing a set on a 2014, but first have to bake them in the oven to heat up the original blue! I will post before and after

 

Looking forward to the process and results

 

Same here- look forward to progress pics.
Cheers, Mike

 

If the 958 headlights are like the 957, then heating them up doesn't help much. Porsche used RTV rather than butyl tape to glue them together. Taking them apart requires a lot of force and there's a high risk of damaging the housing. Good luck though!
I managed to get it done on my 957 headlight, but it took much longer to cut through the RTV and pry out the lens without damage than other butyl glued headlights I had done before.