A landline telephone typically has a base with a handset. The coiled cord that connects the base to the handset has an RJ22 connector on each end of the cord, one that plugs into the handset and the other into the base. The RJ22 connector is smaller than the RJ11 connector that is used to connect the base to the telephone service. If your coiled handset cord becomes damaged, you can cut out the broken section of wire and install a phone cord line plug connector RJ22 on the end of the wire.
Disconnect the coiled handset cord from both the handset and the base of the phone.
Cut the coiled handset cord to remove the damaged section of cord. Discard the damaged section.
Insert the newly cut end of the handset cord into a telephone wire stripping tool. Squeeze the handle of the stripping tool to remove the outer sheathing from the cord.
Hold the cord so that the green wire is on your right. Place a new RJ22 connector onto the end of the wire, with the tab on the connector facing upwards.
Slip the connector with the inserted wire into an RJ22 crimping tool. Squeeze the handle of the crimping tool to compress the connector onto the cord.
Remove the connector from the crimping tool, and plug the repaired cord into the handset and base of the telephone. Test the phone to make sure it is working properly.