Coconut oil is the best oil to use for oil pulling and to get the best results.
But yes you can use Olive oil for oil pulling if you prefer the Olive oil instead.
Take a tablespoon of the olive oil and put it into your mouth and swish it around for a minimum of 5 minutes and then pull the olive oil through your teeth.
The longer you can swish the olive oil around your teeth the better the results you'll have.
Besides olive oil, sesame oil is another good oil for oil pulling but like I said you'll get the best results when oil pulling using coconut oil instead but either will work.