How to use animal crossing new leaf clothes qr codes

1 go to the qr code machine 
2 say you want to use a qr code
3 select the design you want to replace 
4 hold your camera over the code and scan 

It's quite easy! :-) You unlock the QR code machine by talking to Sable (located at the Able Sisters' shop. she's the brown porcupine sitting in the back!) for ten days in a row. Eventually, once it's unlocked, you can walk up to it. Proceed to press the A button! She'll explain a little about it and allow you to use it. She'll ask you to replace one of your current designs by a new design. Then all you have to do is line your camera up with your desired QR code.

A burette should be used to measure the acid's volume. This is because it has accuracy up to 0.05 cm^3 and will help provide her with a value of concentration up to two decimal places, which is required for her experiment.