Implementing ISO 45001:2018 follows a fairly simple path, common to all ISO management system implementations, where you identify the requirements that need to be put in place (including Iso 45001 as well as legal and other requirements), then you identify how you will satisfy these requirements for the organization. Using this information, you put in place the policies, processes and procedures needed to meet all requirements, use the processes to gather records, and monitor and improve the management system through internal audit, management review and corrective action. Finally, you will have auditors from a certification body come to verify that your processes meet the requirements of ISO 45001.
As for incorporating ISO 45001 into an IMS, this is certainly possible and often preferred. Both standards now follow the same document structure so it is easy to see what is common, such as internal audit, control of documented information and management review. In this way you can even use the same processes and procedures for these common elements and ensure that you cover both aspects of the processes.