Instead of buying new headlights I’m restoring the oem. What is the plastic piece called in front of the turn signal? It is yellow and I wanna open my headlight up and replace it, or restore it if possible.

 

I believe those are yellow/amber from the factory to diffuse the turn signal light (unless you are talking about the textured lens covering over the entire turn signal area, that is NOT supposed to be yellow in any way!). Aftermarket ones are clear, but most people toss them when they put in LED turn signals.
I have clear ones laying around if you are interested.

 

I’ll buy them off you if it’s the part I’m thinkin about, it’s like the cover OVER the signal light . The other one is clear