98 gmc sierra 2wd 5.7. How hard is it to change out the rotors.

 

Not hard at all...
Remove wheel
Remove Caliper (2 - Allen Bolts)
Remove Center Cover (use flat head or flat punch)
Remove Cotter Pin and Large Nut
Pull it off (there will be a bearing in the front and rear and a seal in the rear only)
Good Luck!

 

Then reinstal in reverse order, but you will have to repack the bearing with greese and get the torque specs to torque the wheel bearing.