Further to my earlier post please see off the immigration website. Best of luck
The two most common ways you can apply under ENS or RSMS are the Direct Entry and the 457 Transition streams.
Direct Entry Stream. Under ENS an applicant needs to obtain a skills assessment in their occupation and have a minimum of 3 years work experience in their occupation - anywhere in the world. Applicants also must satisfy English language requirements, medical checks, and character checks. For RSMS applicants need to have a relevant qualification to their occupation. Tradespeople though are required to undergo a skills assessment in certain circumstances.
457 Transition Stream. Applicants have to have worked for the employer nominating them for permanent residence for 2 years on a subclass 457 visa in Australia. No formal skills assessment is required and lower English language requirements. Medical and character checks are still required.