How do i replace calipers and wheel barrings?

i have a 94 s10 and i need help on how to change the calipers and hoses and bleed the brakes and also how to replace/tighten/pack the wheel barrings.. thanks!! details would help alot! and if you know any mistakes that could occur and cause major damage.. please warn me!! its a 4.3 vortec v6 automatic RWD.. if i change the front calipers do i have to bleed all four wheels?? how exactly do you bleed the brakes?