new tubes on auto-bias amp,can be done by anyone?

could i just simply put NEW tubes on an AUTO-BIAS amps? as long as the PAIR/QUAD tubes are matched?!? right? 'coz every time i called-up the manufacturer,,,they always recommended sending the amps to them,,,SO HASSLE,,, physically & emotionally,,,i can't get a straight answer from them,,,was it just their another marketing strategy? or they were being SOO...HONEST,,,my objective is TUBE ROLLING,,not for a repair,,,,thanks