Remove the Homelite chainsaw's spark plug wire with pliers.
Use the combination wrench that comes with the saw to remove the bar nuts. Slip the nuts out and remove the clutch cover and the bar.
Unscrew the bar oiler cap and drain the oil into a drip pan.
Remove the oiler plate with a Phillips screwdriver. Clean out the plate and crevices around it with the tip of the screwdriver, removing oil and sawdust. Also clean the oiler hole one the bar.
Remove the clutch drum and the brake band with an Allen wrench.
Remove the oiler pump retaining screws with the Phillips screwdriver. Place new pump in place and tighten it.
Replace the brake band and clutch drum with the Allen wrench.
Replace the oiler plate, the clutch cover and the bar and slip the bar nuts into place. Tighten the bar nuts with the combination wrench. Fill the bar oiler tank back up with oil.
Replace the spark plug wire, start the chainsaw and test out the new oiler pump.