You can also use a pre-polished connector instead of splicing e.g.: https://www.fs.com/de-en/products/35165.html https://www.fs.com/de-en/products/35165.html (

You can also use a pre-polished connector instead of splicing e.g.: https://www.fs.com/de-en/products/35165.html https://www.fs.com/de-en/products/35165.html (there's instructions if you scroll down)