To use the freebet you only need to clear the previous selections from your betting slip and afterwards select the new event(s) you want for the new slip.
In the Betslip you should then choose, within the box provided for this purpose, "Select an offer" and choose the freebet you want to associate.
Please take into consideration that the Freebets may have minimum odds associated.
You can check in video how to use a freebet by click here.