Shut off power to tank and turn off water supply/ drain water from tank using water hose attached to drain valve/ disconnect electrical connectors from elements and using vise grips, unscrew elements/ apply anti-seize tape or paste to new elements and insert in tank/ reconnect electrical connections and after disconnecting hose, refill tank /turn on power
First thing to is to shut off the ELECTRIC!!! Determine if current is 110 or 220. Most 220 heaters are two elements. Un hook the wires from the elements and take OHM meter and put it on direct current test both screws if the needle moves showing current element is good the element that doesn't show current is the one that needs replaced drain the water from heater and replace bad element(BE SURE TO FILL TANK ALL THE WAY UP AND LET PRESSURE OUT OF THE POP OFF VALVE WIRE ELEMENTS BACK UP AND TURN POWER ON.) (IF THE TANK NOT FULL OF WATER BEFORE POWER IS ON IT WILL BURN THE ELEMENTS RIGHT BACK OUT.
Turn-off the power to the heater. Drain the tank.You'll need a special large socket tool to unscrew the element available wherever you buy the element. There is usually two elements ,one upper and lower.you can use an ohmmeter to check which one is faulty.
Is there a right and a wrong way to put the wires on the element in the hot water heater to make it work