1973 CB450 External Oil line

Discovered my CB 450 has an external oil line that goes from near the underneath of the stator cover to back behind the engine.    I *think* this line is leaking oil and needs to be replace.   oil has been leaking from somewhere until I discovered this oil line exists.   I drained the oil from my bike until I can fix this.

Is the line rubber or steel with a rubber coating ?  How can i replace this line ?   It seems one needs to pull the engine to do the replacement.