This is novice. but, is it possible to do lowering springs on stock shocks? if so, how ? Or there has to be coilovers for lowering the car?

 

Yes.
Ride quality won't be that great with stock shocks. Also, it can wear old shocks quicker. Others will say they've been lowered with stock shocks for years with no problems.
So do so at your own risk. Results will vary. Search function is good too. Simply typing in " lowering on stock shocks" or even "lowering springs" would've brought up lots of threads for you to read lots of info