Before you rename the file, click tools at the top and go to folder options. Click view at the top of that window and make sure Hide extensions for known file types isn't ticked. Then when you rename it you can change the file type as well.
Both? That's how you unlock the files. You need to do all the instructions. There is a more detailed tutorial somewhere on the forums. Search unlocking files.
There isn't much point giving the LES the standby command. The standby command allows a unit to be called as backup or sent with a battalion chief. There is no command to send an LES yet.