In a joint tenancy, what specific legal action is required to transform the ownership interest into a tenancy in common?

To transform a joint tenancy into a tenancy in common, a joint tenant must perform a legal act of severance. Severance is the legal process that destroys the right of survivorship, which is the defining characteristic of a joint tenancy where a deceased owner's share automatically passes to the surviving owners. The most common way to accomplish this is through a unilateral conveyance, where a joint tenant transfers their intere....