Collant drain plugs on engine location?
 

I cannot seem to find coolant drain plugs on short block underneath i know every engine has it so can someone assist i want to do full drain.

Need exact location better with a picture.

P.S. Tried getting off heater pipes however i cannot manage it safely its too tight.

99 times out of 100, that plug is stuck on tight and no amount of force will get it out without damaging the engine block.
But, I wish you luck to find it and remove it.

I just looked through all diagrams for the 99 Accent and I could not find the plug you are looking for. If you want the best flush I would suggest using a coolant flush machine.