Gather what you need First gather your tools and equipment. You will need a power drill eye protection work gloves and a blade sharpening kit. The kit should come with a ceramic blade sharpener and balancer. Expect to pay about $8 for the kit at your local hardware store. You will also need a torque wrench (or a socket wrench in a pinch) and a wooden block. Consider having a rubber mallet on hand too.
To clean it first start with a cool engine. If your mower has a fuel valve switch it off. If you can disconnect the spark plug too. Next use a leaf blower to blast away any old dirt and major debris. Now gently lay the mower on its side fuel cap facing up. Try to get rid of any junk on the mowers underside as well.
Get out there and mow Now that you have done all that your mower should be ready to tackle the season in stride. It should run smoother and more safely too. Even better you have just saved the $200 to $300 fee it typically costs at least in my neck of the woods to have your lawn mower serviced professionally. So go on and get out there. That high grass needs cutting.