We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember MW saying
something like:

Problem is I can't work out how to get a look at the element, and how
you get at it without oil coming out. And my very low level diy skills
have a track record of me thinks typically making things worse..

The ones I've seen are like a mini immersion heater and simply screw in.
There may be other types that I haven't come across, of course.
Obviously you'd have to dismount it from the wall and have the element
end at the top of the rail as you hold it, so the oil stays in.