First thing is to define for yourself what a grinder is. Are you talking about grinding cash games, MTTs, SNGs or some combination? Does it mean playing at least X hands per day? per week? per month? Does the stake level matter?
Then, once you've figured out your definition, the next step is figuring out how you're going to get there from where you are now. This includes not just how you plan to increase your hands played and move up in levels, but also how you intend to improve your game. In this regard, somewhat contrary to what you said, while learning does require playing to gain experience, just playing may well be sub-optimal compared to playing plus various forms of studying, possibly in combinations depending how you learn best.