When you open the skill in Amazon Developer, you should see a tab to add a new language.
After you select the new language, and input the skill name and intent, the ARN gets copied over from your U.S. skill, but nothing else.
So the biggest PITA was if you try to add – say – the main EchoSistant schema, and then try to add the custom slots, the skill will try to save after adding each slot but errors out because the schema references slots that aren’t present yet (I hope that made sense).
The work around I found was to spoof it at first just to get something built using a schema with only one slot. I actually used the EchoSistant profile schema, sample utterances and slot.
After the spoofed information was saved, I went back and added all of the real custom slots, then the actual schema and sample utterances.
And that’s it The weird thing was having to spoof the schema, slots and utterances. But for some reason, when Amazon copies over that ARN, it makes building the skill a real headache.