**Hint:** you can easily show that $\ln(n!) \geq c n\ln n$ for some absolute constant $c >0$. From there, $\frac{1}{\ln^2 n!} \leq \frac{1}{c^2 n^2\ln^2 n}$, and conclude by theorems of comparison.
**Hint:** you can easily show that $\ln(n!) \geq c n\ln n$ for some absolute constant $c >0$. From there, $\frac{1}{\ln^2 n!} \leq \frac{1}{c^2 n^2\ln^2 n}$, and conclude by theorems of comparison.