First of anything else , you need to buy insurance or Takaful for your car first. Once JPJ approved your policy and your policy able to be printed out then you can go to MYEG website to renew your road tax online.
here is tutorial on how to renew your car insurance online without leaving your home.
Here is where you can renew your can insurance online.
You need to register on MYEG website http://www.myeg.com.my
once you logged in , you will see the page below
Now you click on Jabatan Pengangkutan Jalan button . it will take you to this page
Click on the Roadtax Renewal , and then you can fill the fields needed in order to renew your road tax
After everything filled just click proceed for payment , the delivery charges are as stated above. The payment can be made via FPX , maybank2u or Credit Card.
Once the payment made you can print out your receipt and wait for you roadtax to be delivered to the given address.