Thank you everyone for your help.
In response to hj’s suggestion, he was exacly right. Right after I sent my message, I tried again and they came off, however, because of the corrosion of the hole, and the screws they would not tighten, and the element slot was all eaten up with rust, so all it did was leak.
By the way, I took the old elements to the hardware store, they tested them for free, they told me the bottom one was bad. But now that its leaking due to the rusted out element slot, I have decided to get a enw heater, a larger one in fact…