Trusses are not allowed to be modified or cut.  Doing so can significantly compromise the structural integrity of the roof system.  If you need to modify an engineered roof system, consulting an engineer is necessary.  At a recent home inspection in Oak Harbor on Whidbey Island, I discovered a handyman/homeowner modification where the truss metal plate was removed and the truss notched to accommodate the garage door opener.  Viewed from outside, the roof was clearly sagging.