Weeell, except for one really annoying added difficulty. Here you will notice that you have both gates in perfect view, so nothing is stopping you from just standing there sniping without moving an inch until the 5 minutes are over. You may want to find this spot and try it out BEFORE accepting the quest. Jump on the small gravestone, then hop onto the bigger, crossshaped one, from there leap onto the small ledge in the corner of the wall. The only working one is the corner opposite the main entrance to the left. Once you have it (and near full ammo with it) accept the quest, ignore all the zombies and look for your SNIPING POSITION.
The first thing you have to do is nothing at all and just don't visit Romero until you have better long range weapons, I recommend the STEYR AUG. *this will only work for characters that already are fairly proficient with firearms* If you are like me and you absolutely hate this quest because it just seems impossible to do without some serious luck or celerity 3, you will appreciate my solution.
