dads honda 300 4x4

Hey yall my dad has a Honda 300fw fourtrax 4x4. I have been noticing that his springs aren't doing as good as before when we had got it. Mainly on the rear end, it will rub the back fenders. should i replace the rear shock or could i buy a spring pack from High Lifter to help the drag out? If yall have any ideas please tell me on which i should do.
Thanks,
Blake