Instructions
Download and install the Supercomputer mod (see first link in References). Install it by placing the Supercomputer configuration file into the Packages folder in the "Sims 3" installation directory on your computer.
Load the game and choose the Sim you wish to play as.
Purchase a computer in the game if you do not already have one.
Right-click on the computer and select the "Master Controller" option, which will bring up a list of all the Sims.
Pick the Sim or event you wish to modify. Alter the settings you want and click "OK" to save the changes.