Shimano Nexus Inter-8 Dealer's Manual page 30

3.
Remove the inner cable fixing bolt unit from the cassette joint
pulley.
• If it is difficult to pull the outer casing out from the outer
casing holder of the cassette joint, insert a 2 mm Allen key
or a #14 spoke into the hole in the cassette joint pulley, and
then turn the pulley to loosen the inner cable. Then remove
the inner cable fixing bolt unit from the pulley first, and
after this remove the outer casing from the outer casing
holder.
Note:
When remounting the cable, refer to the section of "Installation of the shifting cable".
Inner cable fixing bolt unit
30
Cassette joint pulley
Pulley hole
2 mm Allen key or #14 spoke