By the looks of the picture they appear to be the same that I have in my barn. Though there are slight variations depending on brand. I have several different brands that were installed at different times.
But they are all the same when comes to replacing a bulb. The cage screws/twists off the outer threaded ring of the fixture. Just like screws twist it counter clockwise.
Some cages clamp on with a screw clamp at the base or 1 or 2 on the sides of the cage.
The glob twists off the same way. Even though the fixture is aluminium and doesn’t “rust” it can and does get stuck on when not taken off for a long time. It can oxidize and acts like rust.
My globes get stuck also and are difficult to unscrew. Mine are very thick glass so you can apply a lot of torque.
Ever since the first time it was a PITA to get the cages and globes off I apply or spray some oil on the threads before reinstalling everything.
Not sure why you are opposed to using W-D in the barn. Pretty harmless stuff, not a lot needed. Use the “straw” that comes with it to direct the spray into the joints with little to no over spray. That’s what it is for.
Personally I prefer PB Blaster. I find it much better than W-D for loosening stuck metal things.
These days there is no reason to use hot incandescent bulbs. Using low voltage bulbs saves money. They don’t get hot which is a large part of “things” getting stuck.
Low voltage covered or not will never get hot enough to cause a fire if dust and or cobwebs cover them.
These must be mounted pretty high if falling off a ladder may lead to a broken leg. I’ve come off plenty of bucking horses and was at least 8+ feet off the ground. Have yet to brake anything.