Unplug the dryer from the power source.
Push down on the clips on the underside of the top panel with a screwdriver to release the top panel from the dryer.
Remove the screws that go down the front panel of the unit. Remove the front of the dryer.
Pull on the dryer belt and remove it from the drum. Remove the screws from inside the drum and pull the drum out of the unit to expose the pulleys underneath.
Wipe off the pulley wheels that the belt rolls along. Drop two to three drops of oil onto the pulley shaft to lubricate it.
Reassemble the dryer and test it for squeaks. Allow it to run a while so the oil gets a chance to penetrate the pulley.