Thanks Thom and Merudo,
I also replaced my 2230 for the Intel Centrino N-6235 in our new Dell 17R. Everything works fine.
It was the first time I opened a laptop so I found it a bit tricky. After watching some YouTube movies I tried it. The wifi card is below the keyboard. I removed all screws from the back, also in the battery compartment and behind the lid. Just not the harddisk screws. Then I carefully lifted the keyboard using a screwdriver in the slits at the top. This was the most tricky, it got it loose on the top right and then pulled it while sequentially from right to left unlocking the locking mechanisms with a screwdriver in the slits with a levering top-down movement. After turning the keyboard its connector could be removed after flipping the grey locking bar open upward. Now the wifi card was reached. Finally removing the antenna connectors by careful upward lifting with a screwdriver and one more screw. Then reverse the procedure after replacing the wifi card. Make sure you ground yourself and have your data backed up.
Hopefully this is helpful for you!