When changing a clutch cable I like to do a full clutch adjustment at the basket at the same time after the new cable is installed. As far as having to back off the adjuster in the basket prior to swapping the cable, no. Swap the cable then adjust the basket, then adjust the cable.
If the ctuch was adjusted properly there is no need to readjust the center screw at the hub. Nothing changes in the ramp/ push rod/ center screw length from a cable R&R.
You will however need to readjust the cable after about a 100 miles from initial stretch.