The cable routing depends on if you are working on a 1970 or a 1971-74 E-Body.
The 1970 has a one-year-only bracket and metal clips. The 1971-74 has the plastic clip and metal clips.
The metal doors all have the hole prepunched for the remote mirror control.
Your interior door panel should have a hole for the remote "joystick" already there unless your car came with the standard mirror (see last picture).
Otherwise, you will see the location clearly marked on the backside of the plastic interior door panel. Open that up and you are golden.
View attachment 122225 View attachment 122226
View attachment 122229 View attachment 122227
View attachment 122231
View attachment 122232
View attachment 122230