To supplement the good advice given above...

I've tried using the "Encode" module to re-code this to UTF-8, or even ASCII but nothing I do can make this work.

The previous replies have given enough info to read the file correctly. If you want to write the data to a new file using utf8 instead of utf-16le, you'd want to make sure to set the output file handle to utf8 mode, and replace the "utf-16" in the opening xml tag with "utf-8":

open(IN,"<:encoding(utf-16le)","your_file.xml");
{
    local $/;
    $_ = <IN>;
}
s/(xml version="1.0" encoding="utf)-16/$1-8/;

# (that was cheating, but what the heck)
# do whatever else needs to be done with the data
#  -- but use a real xml parser for that... then:

binmode STDOUT, ":utf8";  # or whatever file handle you need to use
print;
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