Wow swshawaii! That link sure makes it look simple. On my '01 I had to remove steering column covers, Shift lever component, dash trim screws and a few other odds and ends. Even then, it was difficult maneuvering the instrument cluster sideways so I could reach in to get at the bulbs. I can't remember if I had to pull my radio too or not. It was a bit of a project and took a while so plan on killing the good part of a morning or afternoon.
I'm not sure if a 2003 has LED's. It could become a nightmare to replace bulbs with LED's if not equipped with them. I've seen somewhere - someone describing that they had problems after installing them with other stuff going haywire and they had to solve it by using resistors. Cheap LED's can also haunt you because there are many different qualities as most are from China and they can be of poor quality. Another thing about LED's, they can have 'hot spots' depending on their design so the dash lighting may not be as great of a display as with original bulbs which spread light better. Be careful because LED's are polar specific when installed, meaning the '+' and '-' position in the circuit panel matters. When screwing one in it is best to turn cluster on to make sure it illuminates, otherwise, turn it around in the socket and try again.
Newer cars that are already equipped with LED's may have some type of semi-transparent plastic diffusers in front of the LED to spread the light to other areas of the particular cluster they want to illuminated.
If the 2003 has bulbs and you just want to replace with the same ones, make sure the package says Long Life or LL after the number.