Migrating Existing Domain from Google Apps to ZOHO

Migrating Existing Domain from Google Apps to ZOHO

I am planning to move an existing domain currently hosted with Google Apps to ZOHO Standard 10GB including transferring existing emails, contacts and calendar for one user. 

Do you have a step by step guide to carry this out without loosing any data during the transfer when the mailserver settings are redirected from Google to ZOHO?

Thanks.