You don't cut the patch and put it on a bowl of weed, what the heck.
You squeeze out a bit and smoke it off of tin foil. Just a pea sized lump and see how that goes. Wait a significant amount of time before hits if you don't know what you are doing.
But that sort of begs a significant question, what kind of person, without any opioid tolerance, would even consider smoking a fentanyl patch.
Wearing whole 75mcg/hr fentanyl patch without a tolerance isn't much fun. When i was 16 years old, zero tolerance, i put a 100mcg/hr patch on (my friends dad had died of cancer and i decided to take ownership of it out of curiosity and play Russian roulette with it). I eventually became very sick, vomiting, i could barely move (it was during a weekend at that same friends house). Yet i wore it for 2 and a half days, it was incredibly strong, the entire duration of which i just sort of crawled from a sofa, to a bed and then to a toilet to throw up, back and forth for 60 hours or so. I remember smiling at my pillow at one point. My friends little brother and his friends were kind of fucking me with me, nicely but still fucking with me, i was so out of it. Not fun without a tolerance, but also not so bad either. I mean i could have taken the patch off but despite the vomiting thought, "hey but its kind of nice too, as long as you stay as still as humanly possible to avoid the incredible nausea".
Back when i was on huge amounts of methadone i used to inject the 100ug/hr patches in one go, nearly 17mg of fentanyl, enough to kill a packed school bus of children. If i tried that now i would dead in around 15 minutes.
Technically speaking, smoking fentanyl is relatively speaking, one of the safer ways of taking it given the ability to titrate it and pharmacokinetics of the drug/fast elimination of it and the relative lack of accumulation in the blood (compared to numerous opioids). Fentanyl's therapeutic index is actually quite a bit higher than morphine, making it comparably safer in known quantities. The problem is, its extreme potency in an absolute sense makes it tricky to handle, especially in inconsistent illicit manifestations of the drug.
But just to be clear, smoking fentanyl is pretty dangerous and can kill you.