change blade

To get to the flywheel brake and where the cable attaches, looks like the fuel tank and recoil need to come off. See illustration included here.

If the cable is bent, rusted, or beat-up, I'd just replace it. The Honda Part Number for the cable is 54530-VA9-000. Be sure to move the spring over when swapping out. A new spring is P/N 53411-VA2-010. Both parts can be ordered from any Honda Dealer; find one close to you with this link:

Find a Honda Dealer Link

-Robert@Honda

Caveat: I work for Honda, but the preceding was my opinion alone.

Taking off a Lawnmower Blade that is seized on the shaft can be tricky and dangerous. Most Honda dealers will should offer to take it off for you for free or a nominal charge. It is certainly worth saving a serious cut or worse. There is always the fear of the lawnmower starting from the rotation of the blade when someone doesn't properly ensure that the ignition system has been disabled (removing the spark plug).

At the shop a trained mechanic would likely use a penetrating oil combined with a 1/2" impact and proper safety gear on (safety gloves, glasses etc.).