You don't and can't unlock a DG-16D5S.
You need to glitch your console to get the CPU key so you can extract C-R.bin and Key.bin from the NAND.
Once you have those files, you need to create an LTU firmware for your drive (1175/1532) and write it to an LTU PCB.
Read
this tutorial to get a better idea of the process.