Would I have to remove the grass in order to landscape with a berm?

I order to make a completely smooth putting green, which should be you goal, I would suggest that you remove the grass and start a new with Bermuda. The whole idea of a putting green is that it is uniform and the same. With a good quality Bermuda and a good watering program, you should have the putting green of your dreams in very little time. Patience is GOLDEN!!

Yes the grass would need to be killed or removed. You can rent a sod cutter to cut through the grass and turn it over as part of the berm. Do not use any landscape fabric when building the berm. Mulch heavily on the surface of the berm.

1. Unless you have an aversion to herbicides, save some labor and just use RoundUp or some other glysophate generic to kill the lawn.

2. You can still pile the dead sod upside down to create berms, but it will be easier to tear up if it's dead already.

Alternatively, you could create your berms out of new, enriched topsoil since you're planning on bringing in new topsoil anyway. Saves a lot of work and expense of renting a sod cutter. Just kill the lawn and then create the berms completely out of new topsoil.

Hey William don't you think that just covering area with cardboard or news paper wetting it down well then piling up dirt to create berm would also work that way grass dies and any weeds since they don't get sun and dirt on top doesn't get any unwanted grass killer in it so this person can start out with clean soil?

I have done Eroque's method before for other landscaping projects. It has always worked well for me. Cardboard is better than newspaper.

https://www.gardeningknowhow.com/special/spaces/creating-and-using-berms-in-the-landscape.htm

If your covering your grass with more than 6" of mulch dirt etc you don't really need to kill the grass fist,-- It will die from lack of light air...