With the mower still on its side grab your socket wrench and wood block. Place the block inside the blade well. This is to prevent the blades from turning while you loosen their bolts. Remove the blade mounting bolt/bolts. A typical mower will have one blade like the Craftsman 37700 I serviced for this guide (one mounting bolt). Some like my Honda HRR216VKA have two blades an upper and a lower (two mounting bolts). Each blade should have at least two cutting edges.
Your Best Digs also recommends the Sun Joe mower but the reviewer also added a number of caveats. He found it will get the job done if you prefer to only bag and just have $100 to spend. However the clippings compartment filled up quickly for him. And the height adjuster felt flimsy and required adjustments on each wheel.
About 86% of the buyers who reviewed the Honda HRX217VKA on Home Depots website gave it four or five stars. Handyman left the most helpful review after using his mower for one year. He noted that its the best mower he is ever owned because of the adjustable speeds for the self-propel controller. He goes top speed and has to walk briskly to keep up. Other buyers remark that the mower cuts well after just one pass and doesnt leave stragglers clumps or lines. One buyer was impressed with how it could even handle unkempt grass over six inches high.