How to remove handle from Danze faucet D304056

I called Danze and they said that the handle assembly can be unscrewed from the top. Mine is too tight. Using a wrench to loosen it - even with cardboard or similar material under the wrench - will mar the soft metal body of the handle. Is my only choice to remove the mounting hardware assembly underneath the sink by unscrewing the two screws, replace the cartridge, then re-install the assembly? Am I missing something? (See drawing)

SOLVED!!!

Used a rubber strap wrench to loosen the handle - was probably put on too tight at initial installation. I needed to replace both the cartridge (yes, it is replaced from above) and the handle (interior threads stripped).