Step one:Make a new document
Step 2:Paste your first image as a new layer.
Step 3:Pick the Select tool.(Make sure your settings are set to;"Selection Type:Rectangle"and"Mode:Replace")(Found at bottom)
Step 4:Select the part of the picture you want to get rid of.Press the delete key to get rid of it.
Step 5:Repeat steps 2 and 6
Step 6:Use the move tool to get the two images together
Step 7:Use the Crop tool top get rid of unused sections of the canvas.
Step 8:Add whatever cool effects you want:)

I hope that helped.Have fun.