A/C recharge

I went to recharge my A/C and when I was taking off the low side dust cap there was pressure coming out. After I let it slowly out and got the cap off I tried to tighten the valve but I couldn't get the tool to go over the needle far enough to engage the valve and turn it. I checked with the auto parts store I was at and they had replacement valves but if I can't get the tool down far enough to turn it how can I get it out? The A/C did work just not very cold. I didn't hear anything leaking until I tried the dust cap. So, I went ahead and recharged it with 12 ounces of 134 with leak detection dye just in case. After it was blowing at 34 degrees F. And all seemed well. I went out of town the next day and the hour and a half drive everything was fine. When I got off the freeway the A/C got warm and almost hot until I picked up speed again. I haven't seen or heard any leaks. How can I get the old valve out to put in a new one? I have tried to find how much my system holds online only to be sent to every site that wants to sell me every part possible but not tell me how much 134 I need or how much oil. The one site I found that came close was for Jaguars all but my X type. They mentioned every other X type but not my simple X type and only X type AWD. And yes there is a sticker under the hood but it can't be read. I even downloaded the service manual all 2000+ pages. It covers all X type but I can't find where it says how much 134 and oil to put in. I don't know if you guys have seen this little masterpiece but it doesn't read like any other manual I've ever seen before. There's about three hours of my life I'll never get back. Any help would be greatly appreciated.