migrate emails from Cpanel to office365 essentials (outlook web)

I need help in migrating my mailboxes over this weekend to a new server. I have my current email hosted on a hosting server usnig cpanel over linux. I want to move 5 mailboxes to outlook for web (office365 essential). and around 20 mailboxes to another cpanel account. Once migration is complete I will change the MX settings for the server. I have found instructions here. [login to view URL] May be there could be better way of doing the same. I need the mails and contacts to be transferred from a regular mail server using cpanel to a two mailservers. 5 mailbox to outook and rest to another cpanel mailserver.