To replace the thermostat on a 2002 Nissan Altima first drain out the coolant. Then proceed the to locate the thermostat housing which is by the engine compartment fuse box. Unbolt the housing and replace the thermostat.
It is located on the backside of the engine. Go to youtube and type in how to replace camshaft sensor on 2005 Nissan altima and it will show where it is and how to replace it, that is how I did my one.
Remove tire, Large bolt on the end the the half shaft, then lower ball joint, then pull the rotor and strut away from the car while pushing the half shaft out of the rotor and using a pry bar between the halfshaft and transmition pry out the axle. Then install new.