How am I supposed to change this?

Had a full rewire done 6 years ago. One of the down lights has gone in the kitchen. Pulled the unit out looking to change the bulb (the ones in the next room are similar but replaceable LED bulbs just twist out).

Presumably I need to change the whole unit? Can't find exact match so just get the next best thing? Doesn't seem sensible the bulb can't be replaced and I need to buy a new £20+ unit every few years.

There's a box further up the wire in the ceiling, which looking at similar units online seems to unplug into 2 parts and I can plug a new unit in?

Any alternate advice appreciated.

Thanks