1999 Nissan Altima alternater

Drain the cooling system below the upper radiator hose level.
Remove or disconnect the following:

Negative battery cable

Upper radiator hose

Alternator electrical harness, harness stay and the harness-to-A/C compressor

Throttle cable

Loosen the adjusting bolt

Accessory drive belt

Alternator mounting bolts

Alternator from the engine

To install:

Install or connect the following:

Alternator and torque the bolts to 11-15 ft. Lbs. (16-20 Nm)

Harness-to-A/C compressor, harness stay and the alternator electrical harness

Throttle cable

Drive belt. Properly tension the belt

Upper radiator hose

Negative battery cable

Top off the cooling system.
Start the vehicle, check for leaks and repair if necessary.