just change the nozzle to a smaller size: 0.25 is great for really fine detail.

Changing the board or extruder won't necessarily give you higher quality.
But a smaller nozzle and the correct slicer settings (slower and slightly hotter with less retraction). Will make a lot of difference.

Basically what you have is - for all intents and purposes - an ender 3.
so go watch all the: upgrade and modification and improvement videos for that. Most will apply.

There are millions - it's not a great design - so a LOT of room for improvement.

But for cheap, quick quality results - smaller nozzle works well. Just be aware that things will take a LOT longer to print :-)