How to replace the transfer belt Ele...

That depends what kind of printer you're dealing with. In general, you should just open a front cover. Then release the ETB from the rest of the machine. Look for two blue handles to release the ETB. Replace the ETB and make sure the printer detects the new ETB. If the printer don't detects the new ETB, try to restart the printer or reset the ETB-counter in -Configue device--->resets----->reset supplies----->NEW ETB.