The general rules and legal procedures followed in most countries in case an individual wishes to CHANGE his/her signature from an existing one are explained here in brief.
1. File an official application specifying your details and carrying the samples of your old and new signature.
2. Inform the departments of your concern about the change. For example Banks, Insurance Companies, Mortgage Companies, Lawyer, Passport Office, etc.
Please note that certain companies might have their own formalities with respect to change in signature that you would be expected to follow. For instance a bank might have a specific form which seeks your old and new signature.
Disclaimer: The procedures mentioned here are only indicative and in the best of the knowledge of Sign in Style. Contact your lawyer/attorney/adviser for exact procedures or try searching for your queries using Google search box provided below.