Okay so i suck at explaining things but I'm going to try my best here.

First, te will open both of these pictures:





Set their size proportions to 533x300. [Make sure te have the option to 'Constrain Proportions' selected - this way when te put in your width, 533, it will automatically make the height the correct size, 300.]

successivo step - now that te have both immagini resized, open a new canvas/blank background & set it's size to 265x265

Drag both immagini to the new canvas - At this point your new canvas should look like this:



te should have Layer 1 underneath Layer 2.

Now to the erasing part - te want to erase everything [on Layer 2, your superiore, in alto layer] to the left of Regina's body and hair.

When te go to erase close to her body/hair, make sure to do it carefully so that te only get rid of the rest of the image & not parts of her. To help make erasing easier, check that your eraser brush settings are somewhere close to this:

Hardness: 25-35%
Size: 35-45

To change your setting, click on the eraser icona and then click on the brush icona along the superiore, in alto bar [below File, Edit, etc.]

Now your icona should look like this:



I hope this was somewhat helpful! Sorry I'm so horrible at explaining things.