It is very easy to replace robot arm of the same series like tx60 to tx60:
1. Power Down CS8C
2. Disconnect old arm, connect new arm.
3. Power up CS8C - it will give you some message about phasing not right.
4. On Teach pendant Main menu: Go to : Calibration: and press/choose "rec" - (recovery option)
It would ask you if you connect new arm and want to copy data from arm to controller - Choose "YES"
5. If everything go smooth - that is all you need to do. If you have any other problem - let me know.
I did that procedure many times.
P.S. first you need to change user in the profile (controller settings: user) to "maintenance" - password available online - do a little search.
I do like Staubli robots - I saw some with 131K + nonstop hours and still running