No. The trademark itself can never be modified. If you change some aspect of your trademark, if you alter your logo for example, you will need to apply to register it as a new trademark. More about modifying a trademark
A trademark registration is valid for ten years. You can extend your trademark registration for a further ten-year period from six months before the expiry date of your registration. More about renewing a trademark
No. The trademark itself can never be modified, not even when you renew it. You will need to apply to register a new trademark to protect your new logo.
