Process of applying Canada Work Permit

My Wife is now in H4 Visa in US with me and her previous manager is ready to give a job offer to work for a Canadian client considering her skills and experience ( she has more than 6 years of experience and in H4 since 2016 Dec ) in a niche technology which is rare in Canada. Its an MNC with multiple clients in Canada.So what are the steps they should follow to hire her ? I have read that a job posting should be done in a job portal for a month and do LMIA before hiring a foreign skilled worker. Could anyone please throw some light on this.