How do you prepare Ritalin for iv use?

Shooting pills is an absolutely horrible idea (I'm assuming the dextro you are referring to comes in pill form) because of all the fillers and stuff in them. I wouldn't IV a pill if you paid me to, and this coming from someone who used to shoot heroin like there was no tomorrow. One big issue is that shooting pills is almost guaranteed to ruin your veins very quickly, much faster than something like heroin would. No matter how good of an IV user you are, you're going to miss occasionally, and with some pills that can be anywhere from mildly to extremely dangerous. For example, if you miss when you're shooting Temazepam, it can literally cost you an arm or a leg. I highly doubt dextroamphetamine would do that, but that doesn't mean it's a good idea. I'm not even being anti-drug here. Snort it if you want to -- snorting amphetamine, like cocaine, gives you a better high than swallowing it does, although that isn't true of all types of drugs. Snort it too much and it can mess up your nose, though. Or if you absolutely must IV something, I think I'd actually shoot coke before I would shoot dextro, especially if I knew what the coke was cut with (probably even if I didn't know). Plus, from what I hear, coke would give you a better high anyway. Sorry not to answer your question, but even for a lot of hard-core junkies, shooting pills is going too far, and you at least need to understand the consequences if you do decide to go that route. Pills simply aren't made to be injected, so if you must IV something (bad idea, trust me I speak from experience), find something that is meant to be injected.