While Microsoft Office remains the dominant office suite, enterprises are increasingly making the shift to Google’s G Suite, thanks in part to its collaboration abilities.

Office 365 boasts some 120 million commercial monthly users, while just 4 million businesses pay to use G Suite–however, that numbered doubled in only two years, and continues to grow, according to Google.

“G Suite is growing rapidly in the enterprise, increasingly at the expense of Microsoft,” said Eric Shashoua, CEO of Kiwi for Gmail. Fortune 1000 companies are in particular making the switch, he added.

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Driving the shift is the fact that G Suite is less expensive, and younger employees tend to prefer Gmail for work over Outlook, Shashoua said. “Google is also really, really good at the collaboration piece, and Microsoft just isn’t,” Shashoua said.

The three factors that make it difficult for many employees to leave Office behind are its software’s more advanced features, dependence on older documents, and fear of change, Shashoua said. The latter ends up being the most challenging, he added. “It’s behavior change, and it affects most people in the organization,” Shashoua said. That fear of change needs to be overcome in the onboarding phase, after the champion leader is on board, he added.

Here are four steps for CIOs who want to shift their workplace from Microsoft Office to Google G Suite.

1. Get leadership buy-in

When examining large companies that have migrated, “the no. 1 thing is getting the leadership to really buy in and take ownership of G Suite,” Shashoua said. “Try to get the big mover as high up in the organization as you can to be using it, to engage with it, and to really want it.”

The challenge here is that many members of the C-Suite have been using Office tools for decades, Shashoua said, and will need seeing the benefits of G Suite and moving over.

“People tend to underestimate how much buy-in they need to get at the top of the organization,” Shashoua said. “If someone decides to bring this in, they need to work hard to make sure that the management of the company understands how it works.”

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2. Anticipate employee resistance

After engaging leadership, the CIO must find groups of people who are essentially the lowest hanging fruit and are likely to embrace G Suite and become evangelists in the organization, Shashoua said.

The finance department is often the most difficult to move over, as they tend to use complex Excel spreadsheets that Google sheets are not yet capable of fully replicating, Shashoua said.

3. Take a multi-faceted approach

Different pockets of users exist in every organization, and the CIO must approach each group with different tools that will help them engage, Shashoua said.

“That multi-faceted approach to different kinds of users is really critical,” Shashoua said. “Sometimes companies make the mistake of trying to approach everyone the same way.”

For example, executive administrators may have three inboxes and calendars they manage, which will look very different on G Suite than in Outlook, and will require new instructions.

4. Go in phases

Companies with more than 1,000 users must be very careful about putting users into groups, and onboarding them to G Suite one group at a time, Shashoua said. “If you try to take on the whole company, or half the company at once, that’s going to be likely to fail,” he added.

This becomes even more important for companies with more than 1,000 employees who are spread out over different locations.

“The larger company you are, the more you need grades of training for your employees,” Shashoua said. Beyond an introductory email, CIOs should schedule mandatory sessions for how to use the tools and deal with common problems, he added.

“It’s not simple to move a company over to G Suite,” Shashoua said. “But if they want to, then taking a cautious and organized approach like this is something which will really help it work, and work well.”