How to say “Yesterday's rose has lost its scent, so let's get another one for the demonstration.” in Japanese

In Japanese

昨日(きのう)のバラ、もう香(かお)りがしないね。説明(せつめい)に使(つか)うの、別(べつ)のに替(か)えようか。

Kinō no bara, mō kaori ga shinai ne. Setsumei ni tsukau no, betsu no ni kaeyō ka.