A good M&A process- is Key. Follow the process and have the right key people on your PMO team to be flexible, when needed. It takes almost as long to choose the right PMO and functional teams as it does the M&A process.
I think the first step is to develop an acquisition strategy, then identify potential target companies (profit margin, location, culture adoption, customer base), search for target companies, begin acquisition planning, start valuation analytics, complete negotiations LOI agreement, begin the due diligence process, purchase and sale contracts, begin the finance strategy, and then close the acquisition, lastly begin post-merger integration process Day 1 -Day 100.
And communicate the process, where you stand in the steps- to employees to keep momentum and trust within this change management phase.