How do I do a simple trim on one layer only?

[musicalbasics]

I'm looking up cropping and all of the guides or tutorials cover cropping in the sense where you crop out a portion of the image, and then the entire canvas is resized to just show that portion.

I have a simple situation where I need to trim out part of the photo, past the white space. However, I do not want the image to be resized, but merely stay in place.

What's the best way to do this?

Also, how does one add a border to the artistic text?

 

[musicalbasics]

Hey, thanks, I really appreciate it, this is a great tutorial for another purpose but I don't want the background to be transparent, I want the same background. Because I plan on adding 3 more images the same size so that there are 4 images total like a collage. 

[laurent32]

With a white background enabled, couldn't we simply use the rectangular selection tool and hit the erase key ?

[user_0815]

• You can also use a shape (rectangle, curve etc.) and set the blend mode to "Erase". This will erase all layers beneath. 
• If you want to only erase one specific layer, drag the shape on to that layer. Everything else will remain visible.

This also works with pixel layers if you want to erase something by using the paint brush. That works like a nondestructive eraser.