这件事情大不了明天再解决。

Zhè jiàn shìqíng dàbùliǎo míngtiān zài jiějué.

This matter can be resolved tomorrow at worst.

这只是小问题，大不了重新开始。

Zhè zhǐshì xiǎo wèntí, dàbùliǎo chóngxīn kāishǐ.

It's just a small problem; if worst comes to worst, start over.

他们要是不同意，大不了我们自己做。

Tāmen yàoshi bù tóngyì, dàbùliǎo wǒmen zìjǐ zuò.

If they don't agree, we can do it ourselves at worst.