hey guys, this is my first post on the forum thought this forum would be relavent to what i need

been running a bulking stack for a bodybuilding show, sus deca dianabol , gains good, going well however i only have about 3 weeks left before im gonna start cutting for my show, this may seem SO silly and SO amature to ask but please answer with no sarcasm, how do i go about going from a BULKING stack to a CUTTING stack? i surely cannot just go from one to another! please help me out guys? thanks!