How much needs to come out when replacing the keyboard?

I have a Mid 2009 15” MacBook Pro 2.53 GHz machine and I want to replace the keyboard. I have one at hand but there is not an instructions for it. There is only instruction for replacement of the entire upper case. How much needs to come out of the machine to get at the existing keyboard for replacement?

I’m guessing that at most, the logic board and optical drive needs to come out. I shouldn’t have to remove the display, I don’t think.

I have worked on MacBook Pro’s from 2008-9 with user detachable battery, logic board in and out, replacement of fans.

I’ve worked on Powerbook Titanium replacing the logic board, tear down and clean after juice spill when the machine as off.

I have also worked successfully on other non Mac laptops and have home build tower machines for use as web servers.

Thank you for time and attention

JK