Thanks for all the replies!
Chain has been properly cleaned, tightened to spec and lubed with Motul Road+ which is a wax-type of lubrication. I have shot a video down below for better assessment.
So, reason I'm considering only replacing the chain is because the sprockets seem to be in quite good condition and it would make the job hella lot easier and cheaper.
But if I do replace the sprockets, could some kind soul give me some guidance as I do not wish to pay 700USD to do so?
I have still not understood the need to remove the rear wheel. Here's the way I imagine the rear sprocket being removed:
1. Put engine in gear, ask someone to hold rear brake and remove big center nut on sprocket side.
2. Cut and remove chain.
3. Remove the rear sprocket assembly
4. Once removed, disassemble the sprocket from the sprocket holder.
5. Assemble the new sprocket onto sprocket holder and put everything back together.
Am I missing something here?
Regarding the front sprocket I'm not exactly sure how I should do to remove it. Any suggestions? I saw a video of a neat way to wrap the chain around the rear axle bolt but that seems to only work on double-sided swing arms.