Alter Existing Image

We have a simple image of a tree with branches on a white background that we would like to use. The only thing is that we want to remove a couple of items from this image, add our own text and re-size this image. The current image we have, has the following dimensions: 393 x 590px, which is about 103 x 156 mm/ 4.0 x 6.1 in. See attachment for the image. Our new image needs to be re-sized to the paper size A2 (594 x 420 mm/23.4 x 16.5 in). We would to receive all of the files including the .PSD file in case that we need to make modifications. This is a relative simple project, but because of time constraint we are not able to do this ourselves. Once we have selected the freelancer that we will work with, we will provide the detailed information.