It would depend on what you perceive the cultural changes as. One example I can give you is that of an India-based tech company that bought a small US-based company.
Challenges:
• integrating the US workforce into an Indian company (people on H1B visas and L1s)
• motivating senior leaders of the smaller company to take on new roles
• aligning the mission and values
• policies, processes, pay and benefits and other SOPs mapping and alignment
Work done:
• creation of high-urgency list of folks to be addressed on priority
• culture change workshops for people from both entities to come together and explore
• clear articulation of expected behaviours and values
• change champions/evangelists to take the change journey forward