Breaking the Bunker is a Tier 5 mission for Black Mous in Call of Duty DMZ where you need to collect a gun from Vondel and use that weapon to eliminate the Rhino and the Sniper boss. Naturally, you need to know the exact location of this weapon and the two bosses, so here's how to complete the Breaking the Bunker mission in DMZ.
Where to find the Phalanx Dead Drop Weapon in DMZ
Breaking the Bunker mission has three objectives, the first of which requires you to collect a weapon from the Phalanx dead drop in Vondel. Located in the northern half of Vondel at the G3 map coordinate, you'll find it next to the University building. (Check the yellow circle on the map image above to see the precise location of the Phalanx dead drop.) Collect the Kastov 762 from this dead drop and stow it in your backpack; I recommend extracting from the map after you find this weapon, as you will need to queue into Al Mazrah with the gun.
How to Find and Kill the Rhino in DMZ
The Factory wing in Koschei Complex is where you will find the Rhino and the Sniper boss. However, to access this area, you need to find the Factory Admin key (which can be collected from the Chemical Plant). Check the vents and the small rooms inside the Chemical Plant to find the Factory Admin key.
Once you have the key, use it to unlock the Factory area from the Chemical Plant. Be careful while getting inside the Factory as there are several AI combatants and Sentry Gun traps all around. Once there, you will find a server room that leads to the Rhino. I recommend going in with a squad and taking enough plates, as this can be a tough boss to defeat.
The Rhino carries a Riot Shield and is ridiculously fast. This boss charges at you, so make sure to move around the area to find better vantage points. Use the Kastov 762 you collected from Vondel to bring down the Rhino's health. If you have enough grenades and other lethal equipment, throw them at the Rhino to stop him in his tracks. After breaking the Rhino's armor plates, keep firing until he gets down to complete the second objective of this faction mission.
How to Find and Kill the Sniper in DMZ
The Sniper boss is located on the second floor of the same area where you find the Rhino. However, this area is rigged with trip mines, and you need to move carefully by going prone to avoid the laser field. Once you get past a trap, deactivate it to make it easier for your team to move around. Keep following the Sniper on the second floor and eliminate all the weaker AI forces to isolate the boss.
The Sniper boss uses a Victus XMR that can knock you down with a single shot, so I recommend quick-peeking the corners and using grenades to cut his health at first. You can use smoke grenades to reduce visibility while moving through the trip-mines area, preventing him from one-shotting you and your teammates. Once you have a clear shot, eliminate the Sniper quickly to complete the third objective of Breaking the Bunker mission in DMZ.