lol Once you start actually working on it you will see why they answered so fast.
You need to move the chain adjusters in a bit to loosen the chain, then with the bike on a rear stand remove the rear axel (you can leave the wheel there if you wish, makes no difference) and that will give you plenty of chain slack to change out the front sprocket.
Make 100% sure you LOC-TIGHT the front sprocket nut. It is HUGELY important!! If it comes loose it can cost you huge, and more importantly you CANNOT see it!! Be safe, loc-tight it!! Use a quality air impact on the nut when you install it.
spend the time needed to 100% insure the rear wheel is straight and the chain is NOT TOO TIGHT when you are done!! Really important!! Common mistakes!!