Before we get into the nuts and bolts of the Honda 21-inch Variable Speed 4-in-1 Gas Walk Behind Self Propelled Lawn Mower we should point out that the model numbers HRX217VKA and HRX217K5VKA are used interchangeably by Honda to refer to this lawn mower and there do not appear to be any differences between the two. That said the best adjective to describe the HRX217VKA is powerful.
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.
There is something Zen about spending an hour or two each week pushing the mower around the yard on a sunny day. The drone of the motor drowns out your thoughts as you work on a task with a clearly defined objective: Making your lawn look its best. Of course the deciding factor between an almost meditative experience and one filled with frustration is often the quality of the lawn mower you have.