how do i do this. do i got to take it into a shop or can i do it @ my home and if so how?

Their was no reason to start another thread on the same as your other post ......

You can not calibrate the speedo yourself unless you have a highend scan tool.

Sometimes you do not have to calibrate anything as with the 18's and low profile tires the actual overall tire height is the same as your stock wheels and tires.

So a tire shop or mech with the proper tools can fix your calibration if needed.

and Welcome to AF!