Here is an example.
If the width is 960px you would change it to 1152px….
If the home-feature-sidebar is 30% and you need to increase it, then you change it to 40%…
If the home-featured-posts is 500px, you would need to change it to 700px…these are only examples, you will have to do the math to figure out the exact sizes you’ll need to increase or decrease.
The point is, if it is a percentage, only increase or decrease that percentage, don’t change it to a fixed width, or px. Same thing goes for any fixed widths, if it is 300px, only increase or decrease that width by continuing to use px.
So keep all percentages and px the same, just increase or decrease them.