Here are a few articles that you should keep in mind.
As with any upgrade always make sure you get a nice current backup of your ePO and EPO database on SQL. The upgrade should be straightforward but as with anything that is IT, your mileage may vary so be prepared. If you have support with McAfee you could always open a ticket and get an updated opinion as these guys take these calls all day long.
Unfortunately we don't have the support currently.
Not sure, how can I get the help from the McAfee support team.
Incremental upgrades do not usually cause issues but can induce issues that you hadn't planned on. As mmcgary mentioned it is usually a case of run setup and advance the screens until you receive your upgrade. Make sure you take the needed backups of the ePO and SQL just in case murphys law pays you a visit. Do your homework and you will probably be in good shape.