Gunsmithing Need help with Polymyr 80 percent lowers

[latinaincovina]

I bought 80 percent (tan - they were out of pink!) lower receivers and they need to be finished now. They are plastic and look very easy to complete. There is a black center that looks like it was pushed in. Does anyone have any experience with these that can point me in the right direction?

 

[1Rosta]

There is a sight on YouTube on how to do with a Dremel tool. I used a small mill to do mine and turned out OK

 

[DroidSniper]

source of the lowers?