Get a oral syringe, suck up what you want to plug, lube your asshole, and squirt it help there
You want to lie on your side for 5-10 mins or you can lie down till you feel it
I don't know how much you should plug cuz I don't know your mg-->ml ratio
I got a tolerance of 15-20 mgs of oxy. The first time I plugged morphine I did 90 mgs and had the nod from heaven but a little to heavy. The last time I plugged it I did 45 mgs and was good but for harm reduction sake try to plug 20-30 then go up from there
If your solution is say 20 mg per ml then plug 1-1.5 ml
Edit: oh and compared to oxy I like it. That 90 mgs I plugged the one time is my top 5 nods. It was 3 hours of energy followed by nodding my dick off for 6 more hours
I like it but not more then oxy even tho its definetly a good replacement just a little more sedating IMO