Keto is pretty damn simple, especially if you are already dieting successfully. Just drop the carbs out of every meal. You can do a cyclic ketogenic diet or timed carb diet whereby you only take in carbs intra and post workout and you will still reap some of the benefit, but you can also create an insulin spike via BCAAs, glutamine and Leucine intra and postworkout.
Since glycogen stores hold water, and glycogen gets replenished through carbs, if you drop the carbs down to get into ketosis you are going to have little water stored within your cells. You'll piss a lot.
You can buy ketostix dirt cheap at any drug store or walmart. You piss on them and they change color to tell you if you are in ketosis.
You will look really flat and it will be tough to get a pump, but you will be hard and grainy, and then before you are getting ready to hit the stage, depending on how you look, you can add carbs in the day before to refill glycogen. By this time you'll have minimal water and be dry as hell, so when you add in the carbs without drinking water you'll fill up your glycogen so you have nice full muscle bellies but they will be hard and striated, not watery looking.