well, if u gonna replace rotors, u mite as well replace the pad, unless u got a good amount of oem pads on....if not, i also recommend using axis brake pads
u must take the caliper out of the rotor to change brake pad or rotors
as for bleeding, its not even necessary, but pushing the caliper bac can be tricky, gotta be quick ...but they do sell this lil small kit, for like $5-10, which help u push the caliper back in easily and cut alot of time (expecially if u're new at this stuff)
and this isn't a hard job to do, i suggest doing it yourself and if worst case it don't work, just bring it to a mechanic...
chaning oil or brake pad / rotors is like simliar, just a lil more time required.
DO IT YOURSELF and save those unecessary money...