how can 2D deconvolution be implemented for Wiener-Helstrom deblurring without using the function deconvwnr?

Hello,

I'm new to image processing and currently trying to restore blurred images with the Wiener-Helstom filter, I need to do this without using the in-built function deconvwnr and I don't have an idea how to do this!

Any help or suggestions appreciated!

Thanks, Gavin