VeloPro is designed to pro-actively handle any changes to your future plans.  When you miss a workout, or go well above your TL, the plan will adjust.  Of course, this way you won't be able to see any schedule changes in advance.

Alternately, when you have days on which you know you can't ride, it's easy to let VeloPro know.  From the Training Plan tab, simply click on the day (underneath the workout in the white space) you want to change and a dialog box will show up.  The pre-selected choice is "Mark as Unavailable..."  Just click Save and the calendar will adjust. 

Multiple Days Off - Follow the same instruction as above but after you Left-Click and hold your mouse/touchpad on the first day you'd like to mark "off", drag the cursor across the other days you want to include as "off".  This will select those days and you'll get the confirmation dialog.  "Mark as time off" will be automatically selected. Click "Save." 

You can also use this multi-selection feature to convert whole weeks to workouts or to Trainer Workouts.