Remove wheels...remove 2 taper bolts...adj brakeshoes down...pull drums off...if drums is stuck...spray pennetrating oil on flange of axle and move drum little in and out till the drum come off
If the drum is just stuck (like on a tapered hub) and not fastened with 2-3 screws etc...heat and vibration (and penetrating oil if it can be applied) are the key...
An air hammer works good...a cheap substitute is a pneumatic palm nailer...it works like a hammer and they only cost about $30 at HF...the hard vibration is the key...with light pull with a drum puller...
good luck...