look in theme.liquid to add the javascript to the head
look in header.liquid to find the header HTML in the theme.
Put this in their config:
{
"send_stats": false,
"translate_images": false,
"language_selector" : [
{
"U" : "U",
"T" : "T",
"I" : "OneLinkJS_langSel",
"C" : "C",
"position" : "first"
}
]
}
and the one liner in the head of the document.