Changing my logo – need a new size

I’m trying to change the logo on my website to a new design and I need the slot for the image to be larger (almost fill the entire nav bar).

I had my friend change it, but he said the logo was stuck at 185 X 51.

https://www.pierrelacour.com is the website. “J. Pierre LaCour” is the logo that needs to be swapped out.

From my perspective it appears that we need to remove the padding and the border to get it done. Any ideas? My friend thinks that he would need to increase the size of the image and that would increase the size of the nav bar (which I dont want).