Volvo Repair: Procedure for replacing S70 AC Orfice Tube, ac system, serpentine belt

Question
I want to replace the Orfice tube in AC System on my 99 S70 Volvo. I know it is in the engine compartment on the right side in the engine compartment. It looks to be in the high pressure line leaving the fire wall going toward the front next the metal covering the wheel well belowpower steering fluid container  etc.  the front cover of the timing belt
or something on serpentine belt side of Engine.  
I am clueless,  I Do Not know how to start to get to this piece.
1. Can you explain the procedure of how to get to the Orfice Tube? How to get it out?  It is totally HIDDEN?  YOU have to be a Magician to get it.. The system is
evacuated & has no pressure.
2. When I get it in, the Orfice Tube,  Do I charge it with just freon or do I need to add AC oil?
Thank you for any help!!!!!

Very Respectfully

James

Answer
James, why are you replacing that thing?  Did you change the compressor?  Basically they are a pain, thats why you dont change them unless something major like a compressor has gone bad.  You arent going to have any pressure when its evacuated.  You probably have a leak somewhere else like an evaporator.  Its a common issue on the 70 series to have leaky evaporators.  Let me know.  ROger