welcome to the site
I would suggest starting with getting yourself a service manual for your atv
there are free downloaded one's out there if you do a search, and or can always try EBay for a used hard paper copy one, or buy new too
that will give you a idea on what is needed to correct things, once you pin point what is actually wrong, as till you know what is wrong/causing the issue, , hard to say how hard or not something is to fix, and also comes down your skill level
as what one person finds easy another might not if you follow!