Create a new blank layer, copy it to the blank layer with imitation stamp, and finally select the copied blank layer and press CTRL+T to reduce the head to the size you want. The specific steps are as follows:

1, open ps and drag a picture directly into it.

2. Use the quick selection tool to select an avatar.

3. press ctrl+j to copy the avatar.

4. Then press and hold ctrl+t to freely transform the avatar and adjust the appropriate angle.

Follow the tutorial step by step, and you should be able to achieve the desired effect. But if you want professional results, you can study or find professionals to do it.