Xīn zǒngcái rùzhǔ gōngsī hòu, tuīxíng le yīxìliè gǎigé.
After the new CEO took over the company, a series of reforms were implemented.
Tips
usage
入主 carries a sense of taking decisive control, more powerful than simply 'joining.' It implies assuming the top position or dominating a space (market, organization, territory).