Yes you can. Its not really recommended, it would be easier to find something more pure. Um I've tried it and it does work. Um your going to want to crush up the pill, and add quite a bit of water [ this is cause the there will be a lot of powder and the water will get thick [ I would recommend using like 100 to 150 units of water cause when you cook it some will ear off.]Then you are going to want to cook it or heat it up till it boils. Once it boils, remove the flame then let is sit string and then putting it back on the heat again. Do that about three times. Then your going to find some type of filter like a little pierce of cotton usually works, that what I use.Once you have heated up the solution, put the little piece of cotton in there and draw back the liquid through the cotton ball into your syringe. You should get from anywhere from 90 to 100 units maybe some more depending on how much water you put in there.Draw it through the syringe, it should be a cloudy white liquid. Once you have done that, remove all the air out of the syringe and then find a vein, make sure you have at least 2 units of feedback [ blood] from the vein, and then go for it. I would recommend it slow to semi slow. If it burn then your not all the way in the vein. Do not muscle it because it isn't worth the pain and its horrible. Well there, it dose work and the high is kinda nice. If you have any question then shout at me.
If you IV hydrocodone you have a very real risk of pulminary edema which could lead to death hydro has a pretty high bioavailability so slamming it would not really offer much of an advantage for the amount of risk involved if heroin had the same bioavailability I don't think many people would IV it either the risks are just not worth the payoff
The only way to do that is by a process called cold extraction. It's a pain in the ass, and it usually doesn't work out. You're better off chewing them. Snorting all that APAP is awful on your nose. If you must shoot up google cold water extraction.....I think there's a few sites that take you through it step by step
I guess you could, but who would want to? I would think all the tylenol thats in it would make it to clumpy, so maybe not, I don't think it would be wise , if you're at the point of needing to inject something to get high either shoot something shootable(which I firmly disagree with, it will make life worse than you can imagine) , or......get some help