Hitman 2 - Tools of the Trade Achievement
The video below shows me using the prologue/legacy levels, and using the Freeform Training mission with the target Kalvin Ritter. This achievement does not require you to complete the mission. When the mission starts, grab a remote explosive and the lockpick from the crates nearby and approach Kalvin like in the video . Make a save file once you've reached the bar undetected and Kalvin and Mr Norfolk are having a conversation.
For the ballistic kill follow Kalvin and Mr Norfolk and enter the room they are in by the window then simply shoot him in the head and reload the checkpoint once the game confirms that the target has been eliminated.
For the explosive kill, follow them and enter the room the same way and then throw the remote explosive at his feet and detonate it.
For the accident kill, restart the mission. You will require a crowbar which you can find at the back of the boat on a crate after you use the lockpick to get through the gate. You can use a crowbar to release the winch holding the lifeboat on the top floor of the map at the right time to crush Kalvin on the floor below, like I have done in the video. You can also poison his drink with emetic rat poison, which is found on the lower deck in the room next to where you find the yacht uniform, and follow him to the bathroom to drown him as he's getting sick.