@TaraV 

Treat the two black wires at the top of your picture as one wire.

Put them and one black from the HS200 under a wirenut.

Put the bottom black with the other black of the HS200 under a wirenut.

In the wall box should be a group of white wires under a wirenut, remove the wirenut and add the white of the HS200, then replace the wirenut.

This should be done with the power off.

@B.Will Thanks Mike and Will for the inputs. Just want to get some more clarifications and try once. If not, I will call an electrician. 

The top black wire with Red arrow is connecting switch 1 and 2.That is where i got stuck.  I just added numbers and colors to each switch for more clarity. my only doubt is how to connect the black wire with Red arrow on to 2nd switch when i connect the TP link switch.  I am clear with switch 1 connections.

@TaraV 

Treat switch 2 the same as switch 1.

That will leave the jumper between both switches, so that a change in the future will not effect both switches.