I'd like to exchange this.

我要换一个。

同一单元的其他句子

• How much does this cost?这个多少钱？
• Can I try this on?我可以试穿一下吗？
• Do you have this in other colors?你们有其他颜色吗？
• Do you have this in a larger size?这个有更大的尺码吗？
• I'll take this one.我要买这个。