Sprocket changes are pretty easy.
Just need some basic tools.
If you mod the rear, you may end up needing a longer chain.
You may be able to drop the front a tooth, ang go up 1 or 2 in the rear and use your existing chain.
Ideally you would replace both the chain and sprockets... but what ever.

Be careful with the countershaft nut and do not foret the o-rings on the master-link.

Do it yourself.... learn how..... have fun...