If you are working hard to get cut but don't want to lose your size you have to follow a few rules.  Most men that were skinny is to gain weight, gain size, and gain strength.  Once you gain the weight and strength many men find it is too much for thier body structure.  After bulking up many men desire to lower body fat without losing size and strength.  

You don't have to go on calorie deficit or over do the cardiovascular work with could decrease your size and strength. You must find the balance between enough cardio to lose fat, eating enough to keep your size and mixing heavy and light days.

The first step is to add cardio days to your workout.  At the same time you need to keep your calorie count high with good low fat foods.  Cardio and high reps is what you need to do  on some of those days to cut up. 

You should have days that you lift heavy and with lower reps to maintain your strength and size.   Then have days where you go lighter and higher reps.  These days gives your muscles that cut look.