How to change interface names back to the standard eth0 wlan0

[paul]

Hello,

I would like to change network interface name from enxxx back to the 
normal eth0 and wlan0 for my Debian Stretch (9) live build. The method 
most given for changing the nic card name back to the old names is to 
edit the grub file in  /etc/default/grub with adding the following line 
to GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0".  However, I don't 
have a grub file in my /etc/default folder.  I've read the manual and it 
doesn't say anything about grub.  Does anyone have an answer?

Paul