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This part of the taming process involves both of your hands, so it will be easier to remove your budgie from their cage. You can choose a neutral room that he has become used to, such as the bathroom,  or they can stay in the same room as their cage. Teaching your budgie to step up will be easier to do when you are sitting down. Sit down slowly and gently so as not to startle your budgie or cause them to fly off your finger. Use gentle pressure against their chest just as you did when you initially taught your budgie how to step onto your index finger. Push up against their chest as you say ‘step up.’ Keep doing this until your budgie steps up onto your finger. Consider making this a daily activity. Soon it will become a habit for your budgie.  Your budgie may not be familiar with this verbal cue, so it may take a few tries before they understand that they should step up onto your other index finger. Give him a small treat each time he steps up. As with the other aspects of the taming process, you should practice this several times a day in short sessions (10-15 minutes). Stepping up usually comes naturally to budgies, so it probably won’t take very long for them to learn how to do this on your index fingers.

Summary:
Have your budgie step onto one of your index fingers. Sit down in a chair, on the floor, or on a bed. Place the index finger of your other hand on your budgie’s chest, just above their feet. Practice this until they can step up onto your other index finger without you having to push on their chest.