Review the list of required documents to determine what your museum is missing or needs to revise. Include the results of this assessment in institutional planning discussions.
Plan and allocate resources, and build the capacity (human and financial), you will need to support the accreditation review process.
Gain the support and commitment to seek accreditation from the staff and governing body (and any parent organization). Consider forming a board and/or staff accreditation committee.
If the museum is going to go through the reaccreditation process, confirm your next review start date and read up on the subsequent review process.
Undertake some type of formal institutional assessment to get feedback on your operations (such as the Museum Assessment Program (MAP), a consultant, etc.)...and implement the recommendations over time. (Note: Participation in MAP is encouraged but not a pre-requisite to apply for accreditation.)
Revisit your mission and consider how and if your operations still support it.