How will you carry out the following conversion: $p$-nitroaniline to $3,4,5$-tribromonitrobenzene?

(N/A) The conversion of $p$-nitroaniline to $3,4,5$-tribromonitrobenzene is carried out in the following steps:
$1$. Bromination: $p$-nitroaniline reacts with $Br_2$ in $CH_3COOH$ to form $2,6$-dibromo-$4$-nitroaniline.
$2$. Diazotization: The product is treated with $NaNO_2/HCl$ at $273-278 \ K$ to form the diazonium salt,$2,6$-dibromo-$4$-nitrobenzenediazonium chloride.
$3$. Sandmeyer Reaction: The diazonium salt is treated with $Cu_2Br_2/HBr$ to replace the diazonium group with a bromine atom,yielding $3,4,5$-tribromonitrobenzene.