You shouldn't ever need to replace the blade unless it gets bent or broken. Just sharpen it with a file, or a grinder if you have it. The blade has to be balanced though. Blade levels are cheap and easy to use.

Take it off the mower, sharpen it, & balance it.

Balancing it can be done on a nail: you need only that the 2 sides balance, not that the weight-distribution be perfectly-even ( no gunk on the blade while balancing, obviously ).

You want to keep the same kind of angle on the edge as Honda had, & take your time grinding it down if you're using a powertool for the grinding ( if you're doing it with a waterstone, you probably want a 80-120 grit, then only bother coming up to 300-400-grit for the edge-finish/microbevel ).

Takes awhile in a single day, & then you're done for a year.

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