I sent an email to the theme support people. They replied me back on email & sent in the email a bunch of codes and advised me to substitute these codes with a bunch of existing codes in my theme's css file.
I have never attempted any change in the purchased themes earlier. I am new to this kind of things.
Please advise me the right approach / process to do it. I just want to be careful before I go ahead and change the codes in the css file.