It's a pretty standard procedure and there are several different methods. Search the forum and then maybe the internet (in general) for 'Sensor Cleaning'
Cleaning Nikon D80
With the right tools and a little care and preparation, cleaning the sensor on a D80 is a simple process.
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A small electronics vacuum will help prevent internal dust from settling on the sensor. A tripod will allow the D80 to be inverted, preventing environmental dust from settling on the sensor. Be very gentle when cleaning the sensor; it is protected by a hard low-pass filter, but that filter could be scratched by a large piece of dust.
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Scratching the low-pass filter will require an expensive sensor replacement. Don't use too much fluid as it could leak into the camera's electronics.
with the mirror up (sensor cleaning mode) blow out the sensor using an air compressor or a hand squeeze air blower. Don't use canned air, or you risk blowing co2 liquid on the sensor.
Personally I use one of these:
You could also "wet clean" the sensor with any number of kits you can buy on the internet, just be sure to be very gentle and blow it out first.