1st way to kill a sim (by hunger)
Step 1:hold down ctrl + shift + c and then type in testingcheatsenabled true
Step 2:go to your sim you wanna kill then go to needs and pull left until fully red in hunger.
Step 3:sit back and watch the show
2nd way to kill a sim (by drowning)
Step 1:make the sim you wanna kill go inside a pool.
Step 2:hold down ctrl + shift + c and then type in testingcheatsenabled true.
Step 3:make their energy level/hunger level go to zero
3rd way to kill a party of sims (by fire)
Step1:buy a stove,a counter and a refrigerator
Step2:make the room as small as possible
Step3:get the party of sims you wanna kill go into the room and delete all the doors
Step4:get an adult sim who you can control to prepare anything once the food is at the stove cancle the cooking and leave the food at the stove soon fire!
4th way to kill a sim (by aging to death)
Step1:make sure the testingcheatsenabled true cheat is on.
Step2:hold shift and find the sim you wanna age to death and press the sim and then click on trigger age transition and keep doing this until your sim is an elder and when you do this again poof he's a ghost
5th way to kill a sim (by cowplant)
Step1:go to buy mode and use rooms go to bathroom and find accends then find the cow plant and then keep doing the interaction until the cowplant grows when it is mature you can get a cake get the sim you wanna kill and then collect the (pie)from the cowplant if you get lucky your sim might live or not
6th way to kill a sim (by electrocution)
Step1:get the sim you wanna kill to get to a good enough handiness skill
Step2:find any electronic and do thinker on it this might take several tries