The orifice tube is in the liquid line which is probably black flex until it turns 90 degrees downward just before it goes into the evaporator where it will be all metal with a larger diameter. There will be a spring lock fitting at that point (a 93 F150 is not down by the condenser as illustrated here but is closer to the evaporator entry point)You will need a spring lock tool (plastic) that fits the size your working with. After you get the line separated put a bit of the correct oil down in the tubing before you try to pull it out as it may be very stuck and require an orifice tube removal tool. I had one tear off on me and had to use forceps. Good luck..c.j.