Get the old AC lines rebuilt with new hoses. Call around to find a AC supply house that rebuilds hoses for home and business AC units. I had my hoses rebuilt with better quality hose for about $40 for both lines.
Can't tell you about how to install the AC lines and what needs to be removed. I'm sure someone else will know.
Power steering hoses (and other hydraulic hoses) can be rebuilt by a hydraulic supply house or a heavy equipment supply house/repair shop.
America: Land of the Free!
1977 300D: 300,000+ miles
American Honda: Factory Trained Technician & Honor Grad.
Technical Advisor to Am. Honda;
Supervisor of Maintenance largest tree care co. in US for offices in Tex.