These don't get "removed", they get cut off. Snip the copper solid wire at the end of those connectors, strip off the insulation and then use wire nuts or some other approved connector to connect the wires for your new light.
Most likely (because anything is possible), the two black wires going into one end of the switch (back stab and screw next to it) are "incoming hot" and "pass-through hot". All neutrals (white) are together (which is good) and all groups (bare copper) are together (which is required).
If your new smart switch has screws:
From the bulk of it, it's definitely magnetic. It has a balky transformer, and will do all "that 70's Fluorescent" behavior: flicker, hum, start hard in the cold, etc.
It uses the "rapid" or "programmed-start" wiring method, NOT "instant-start", so if you replace with an electronic ballast, select rapid or programmed.
Elementary, My Dear
One cable comes from the upstream source (the service panel or another device box).
One cable is the light loop, in which the black (hot) is switched and the white (neutral) is the return. This is the only cable you can identify with any certainty without a voltage test since its path is broken by the switch.
One cable simply passes ...
What I suspect you have (ignoring the grounds) is:
One cable coming in with hot (black) and neutral (white)
One cable coming in white hot (black), neutral (white) and switched hot (red).
The hots all connect together. Do not touch them.
The neutrals all connect together. Add your light's white = neutral to this bundle.
The switched hot connects to your ...
Looks like they just covered the connector and textured everything.
Using a volt meter put one side to the cover plate then one side of the receptacle should show line voltage the other much less or nothing,
there is a possibility of a voltage being measured on the neutral with no connection to a load (called phantom voltage) in that case the lower voltage ...
That rose looks correctly wired for and end-of-line situation. The usual 3 wires in a rose are loop in, loop out, and switch. loop out is optional as it is used to supply power to the next fitting. If all your light fittings are like this, then either each light has it's own cable runnign back to the fuse box, or (more likely) the loop is connected in ...
I had the same question, and it turns out, some LEDs are electronic but not magnetic compatible, and some claim to be magnetic but not electronic compatible. It looks like yours is magnetic, though.
I ended up bypassing the ballast in my fixtures. It's really not that much extra work, and it was worth it to me.
The fixture and the globe should stay where they are.
Below, you've got a stem, a washer, and a nut. When you twist the bottom trim piece counter-clockwise, you should find the nut and washer inside of that. But hold on to the globe just in case the other parts are missing.
My ceilings here in Switzerland have hooks screwed into them to hang the lamps from.
This means that the cables don't have to bear the mass of the lamp.
Do check what might be behind before you drill holes.
There are several problems with this installation already that need to be changed to met NEC, I would say, remove the square box and start fresh. [Make sure the power is off at the breaker before you start] Back in the day when I was in the trade, I had a 3 1/2" dia deep cut hole saw, Electrical supply companies make an "Old Work" ceiling box ...