Locate the gascolator drain

Push the end of the tube into the fuel test jar (found under the left seat)

Drain a small quantity of fuel into the fuel test jar by using the rim the the jar or your fingers to press the upper end of the drain tube to start the flow

Check for contamination (water/dirt/debris)

Verify it is the approved fuel color/type - 100LL should be a blue tint

Pour the fuel back into the fuel tank

Return the fuel test jar under the left seat

Ensure the tube is not leaking fuel