Take out the old elements. Fill the tank with the hot water tap open to get the air out of the line. Then connect power. If you connect the power with air in the system you will melt the new elements. Taking the front or back panel off, will usually give you access.
Washers have belts too.
They are on the bottom and can be easy or close to impossible to change depending on the make of the unit. You might need manual for this one Everyone has different levels of ability. If you want to save some money and don't mind fooling with things you can probably get almost anything going. I know that I touched on only the basic or even sub-basic. But if it saves you a service call I'll feel good.