Bring your hands onto the base´s feet without shifting your weight. Then shift your weight and press down with your hands so that weight i staken from your base´s hands. Bring your shoulders over the base´s feet and never bend your arms.
Keep your elbows and hands steady until your flyer puts weight on your feet. When you feel your flyer´s weight in your hands decreasing then push with your arms until your elbows are fully extended and your hands are above your shoulders. It is important to keep the elbows in when extending your arms.
Stand behind the flyer and take the hips so that he/she does not fall into the base´s face.
Both base and flyer should be able to hold both positions for some seconds.
The transition can always be practiced the other way round. When the base keeps resisting the bending of the elbows the triceps will become stronger, too. The line of the pushing is more important than the strength of the arms.