Ultramarathon Madness

Can anyone give training advice for a 90km mountain ultra?  I ran 3 marathons last year and a 30km mountain run.  I am running a marathon in February and wanted to include it into my training for the Ultra.  The Ultra is in July - If anyone is interested in the run I attached the link.  http://www.ultratrail.it/ Lavaredo Ultra Trail.  It looks awesome, and kinda scary. Thanks, Sam