I do not know how easy or difficult it is. How long, since you bought the car, and what is it, what makes you want to change it? I'v always recommended to drive it as is first, and figure out, if after 6 months, you have issues, you cannot live with. Most, if not all stickshifts are rather tight at first, need time to break-in, and will be smoother as time goes on until they start wearing out and become too wobbly, but in your case, that's a discussion several years away.
Unless of course, you need a quickshifter, in order to go on track with the car, but in that case, you'd probably need a lot more modifications.
So, coming back, what is it what makes you want to change it?