There are youtube videos on opening the case on a Lenovo X-230. Look at them. Opening the case is not intuitive.
There are lists of changes on the Nitro Key site, and on Insurgo site.
Realize that with a Lenovo X-230, there are several parts, which for the original BIOS to work, must be the original Thinkpad parts. Like it must be an original battery, the original WiFi adapter. After the change to Core Boot those issues go away. Although someone once said that an original battery worked better than the substitutes.
Make sure you clear any BIOS Password.
If you do not plug in the keyboard, or touchpad correctly - on re-assembly - the computer will not boot.
Sven, speaking for a T430 said the Samsung pro drive was noticeably faster than the less expensive drives. But you do not have to afford everything all at once.
Keep in mind I gorked a Mobo. So maybe I should not say anything.
But now you have some reading material.