I did the conversion for my better half's kilt jacket (ex sports coat from charity shop). I did it all by hand so that I could make the seams invisible both from the right and wrong sides.

It's not very difficult, but you'll need a good, thin needle, a thimble, and a piece of wax. And the best pressing iron you can get!

Btw when it comes to irons, "good" means "heavy".

Heming