Hey there Creek, I am needing some help.

I am about to do builtin cabinets for one of the rooms in my house. I have built many cabinets before, but this will be my first builtin. There is already drywall where I want it to go, and the drywall is highly textured. I am trying to decide if I would be better off removing the drywall, or if I should just put the builtin on top of the drywall. The floor is stained concrete, so I don't have to worry about flooring.

Any help with what to do with the drywall, or any builtin tips you could share would be great. Thanks in advance for the help.