The icon_uri of the Mint account and the token_uri of the NFT account can be updated with the update instruction.
./hpl-nft update 2ZYMxZojdocSbwcGg4W92H3hVE9qgMBo7XQg9aug6uKs --type icon --value www.update.inco.com
61YTwr4s5yKNpFk5Zxfeicm4we5u1ZhZ17VCE2GADU2VCmm4a6AZpq8DdHNx8RquR6LEjPPwov2fMWySBmABSimf
$ hpl-nft mint-info 2ZYMxZojdocSbwcGg4W92H3hVE9qgMBo7XQg9aug6uKs
Already Supply: 12
Total Supply: 100
Mint: 2ZYMxZojdocSbwcGg4W92H3hVE9qgMBo7XQg9aug6uKs
Name: moon
Symbol: huione-nft1
Icon uri: www.update.inco.com
Mint authority: BRxWruwQv3berDJELRM73dtp7f4712aiodZ6KCY4RLkq
Freeze authority: 97pqCNMq4NUBVa6DSabNiRPQAbtM8ixEDvXYWQCPLxBi
Initialized: true
Update NFT icon_uri is similar to update mint account token_uri. Just set the value of type to asset, refer to help for details.