Step 1-Uninstall whatsapp,if your
trial version is finished,or you want
to extend it for a year.
Step 2-Go to gmail application and
create a new gmail id.
Step 3-Once you have made it,wait for some time (it totally depends
on your connection speed,ideally
you should wait for 15-20 minutes)
Step 4-Go to google play,clickon
the menu button of your android
and choose "Account Settings". Step 5-Once you have done
this,you just need to choose the
new gmail account,you just
created,and download whatsapp
once again.
Step 6-Now open whatsapp,and sign into your whatsapp account...
Step 7-Enjoy!!
Note:- This way you will make it
free for one year,to make it free for
lifetime,you will have to apply this
trick once every year.