Altering size of side bar in PrimeNg

[jscanlon77]

Does anyone know how to alter the size of the side bar in PrimeNG (Ultima is the customisation I'm using)

From digging into Google developer tools I can see that if I make changes to the following - then the correct resizing gets done

.layout-container .topbar .topbar-left.width: 250px - changed this to 300px
.layout-container .layout-menu.width:250px - changed this to 300px
@media (min-width: 1025px)
.layout-container.menu-layout-static .layout-main.margin-left: 250px - changed this to 300px

This gives me the look I want..

So when I delve into the PrimeNg files I find all of the styles in the file _main.scss
the file _layout.scss imports this file.

Presumably the next step is to be able to compile this _main.scss so that the changes will be reflected. However, I'm not sure how to do this (node-sass?)
How does Primeng compile this file so that the change will be shown in the build?