White buttoned shirt
To modify your shirt you don't need many materials. You may need a sowing machine if your willing to sow it but if your like me I don't know to sow and I don't have the time to learn how to do so. You'll just need to take it to a designer or to someone who does know how to use the machine :)
In the Cosplay you'll only use the bottom of the shirt and in the hands. To make it look like the shirt in the picture you'll need more of the fabric. If your going to use this costume to a party or a comic-con make sure to keep in mind the character. Many people make it look allot like more Victorian than they appear in the series.
In the series Alois Trancy uses a dark purple or sometimes a little neon. But if your like me you'll want to use a darker color like in the image. By using a darker color in the coat you need to use a dark green to match.
Modifying your shirt isn't that hard but to make it a little more Fancier use Gold color buttons! Try to look for the ones that have a very old design in them like in the image. Its a very small detail to add so if you have a tight budget just use the plain ones they have no difference... except the Fancy part! :3
They're various other cosplays but if you search more you'll find Alois Trancy.
Hope This Help In Some Way~!
Aiko-chan~!