Kill 5 stunned players.
There's only one possible way to do this, and that's by following around a Scout. Stunning is (so far) only in the game through hitting someone with the ball from the Sandman. To do it in normal play, just make sure you are following around a Scout that has the Sandman equipped. Whenever you see him stun a player with the ball, promptly shoot them in the face a few imes with a rocket. In order to maximize your chances of seeing this, you will probably want to be on the vanguard of every attack.
To farm, simply get two friends, both playing as Scouts (thanks to the lower health). Have the Scout on your team stun the Scout on the enemy team, and then kill him while stunned. It's a good achievement to farm alongside the Scout achievements involving the Sandman, such as the one which involves stunning a player the maximum amount of time through the Sandman ball (Moon Shot).
Note: The title of this achievement is a play on the World War 2 movie released in the 1960s with the same title. This movie (and the book it was based on) showed the D-Day invasion from the perspective of several different soldiers, including those on the German side.
Gore-a! Gore-a! Gore-a!
Provide the enemy with a freezecam of you taunting over 3 of their body parts.
This one is relatively easy no matter whether you are playing normally or farming for it. To get it normally, just kill an enemy player with your rocket launcher at close range, stand over gibbed body, and taunt. It's easy, but it may take a few tries thanks to the quirks of the freezecam. To farm this achievement, you should have a friend stand in a corner while you blow him away, so that you can taunt over his bloody chunks with greater ease. You can't get this achievement with the shotgun or shovel, for obvious reasons.
Note: There are a number of potential references for this achievement. However, the most likely choice is a reference to the famous World War 2 movie Tora! Tora! Tora!, which depicted soldiers fighting against the Japanese. Funnily enough, there is a blog called Gora! Gora! Gora!, which is a blog of an Australian living in Delhi, India.
War Crime Spybunal
Kill a Spy who just backstabbed a teammate.
This one is a relatively easy achievement, especially if you happen to have a Medic on you. Play the game as normal, but be extra attentive as you play. When a teammate nearby dies of a backstab, immediately go after the Spy that did it. The reason that this is so easy with a Medic is simple: in a Medic pair, the Medic is always the initial target. If you turn around and gun down the spy that killed your medic, you get the achievement. Simply be alert, as a good Soldier should be.
To farm this, get a friend as a Spy and another as any other class. Have the Spy backstab the friend nearby, then blow him up with a rocket. You have a few seconds to kill the Spy before the achievement must be retried, and as a Spy only takes two rockets to die, it's fairly easy without weakening. Goes best with Spy achievements such as Identity Theft.
Note: The title of this achievement is an obvious play on the institution of a war crime tribunal. This is a court of war crimes that tries soldiers of any rank for violating human rights, such as engaging in torture or murdering civilians.
Defend a cap point 30 times.
Once again, another easy achievement for normal play. You must stop the enemy from capturing a point 30 times cumulatively. You can defend the point however you want, with killing enemies or walking onto the point both being valid for the purposes of the achievement.THere are a few points that this works especially well on, and any map where the enemy team must assault points while your team defends them (as opposed to both teams doing both) are great.
To farm this, get on an empty control point server with a friend and capture a point. Have him run onto the point, then you run onto the point to block the capture. Then back off and repeat. If you do this 30 times, you will grab yourself the achievement easily.You can also kill him, but that will slow down the process considerably, thanks to respawn times.
Note: This achievement name is a blatant reference to the war movie of the same name (seeing a pattern here?) that revolved around the defense of a hill by Vietnamese forces officially referred to as Hill 937
While rocket jumping kill an enemy with the Equalizer before you land.
This achievement is hard. We're not talking normal hard, but incredibly hard. Firstly, you need the Equalizer, which you get through a random drop or the milestone system. Second, you have to catch someone by surprise. Third, you have to kill them before you hit the ground. Pretty difficult! The easiest way to get this achievement in normal play is to simply rocket jump up to ledges and whack players before your feet touch the ground. It's easier to do if you are low on health before you rocket jump, as at that point it will only take one or two hits to kill an enemy.
To farm this achievement, it's easiest to get another Soldier to help. Damage each other until you are around 80 health. Then rocket-jump towards each other, with you pulling out your Equalizer to score a killing blow. With that, you have the achievement. It can also be done with him simply sitting on a balcony and you jumping in front of him (such as on 2fort)
Note: You can actually land on your target and kill them to net yourself the achievement. It counts, as long as you kill them within a second or two of landing on their head. This is great for enemies that are unaware of you.