Wǒ búzàihū biérén zěnme shuō wǒ.

我不在乎别人怎么说我。

I don't care what people say about me.

Notes:

我(wǒ): I 

不在乎(búzàihū): don't care

别人(biérén): other people

怎么(zěnme): how

说(shuō): to say, to talk about

Example:

A：他们都说你很傻。

     Tāmen dōu shuō nǐ hěn shǎ.

     They say you're foolish.

B：我不在乎别人怎么说我。

     Wǒ búzàihū biérén zěnme shuō wǒ. 

     I don't care what people say about me.