Certify your document from a notary public in your city.
Take the document (or mail it) to The Swedish UD to certify it.
(Ask them to put a regular certification on the document, not an apostille).
Mail the document to Kuwait Embassy in Stockholm
(Phone: 08-... ) with a postage paid return envelope and the required fee.
They will authenticate the certification of the Swedish UD.
The embassy will legalize the document and mail it back to you.
The turn back time is 15 days