disconnect the battery first, safety. pen and paper make a drawing of the back of the alternator and how the wires fit. remove the wires and mark them up with a bit of insulating tape with a bit of paper stuck on it so you can identify. spanners you will need. the alternator will be fastened to the egine oneither one long bolt or two short ones, and an adjuster bolt. loosen all of them but do not remove. push the alternator and it will swing dropping the drive belt slack. noe remove the adjusting bolt then the pivot bolt/bolts and fit the new one in reverse. make sure the drive belt is tight but not over tight you should be able to deflect the belt a little bit.