From the last line of your post, I’m wondering if you’re getting in over your head. 🙁 I do understand that I don’t see the ‘whole picture’ here; just what I’m reading.
Anyway, you should ask for Installation Instructions from the retailer you purchased your Bruce from. At worst, contact the mfgr.. To tell you EXACTLY what you need to do implies that 1) you don’t have instructions, 2) you have them but haven’t read them, or 3) you have them, have read them, but don’t understand. Everything you need to know with the exception of what to do about ripping up, or not ripping up, the vinyl should be in the instructions & warranty paperwork. If you’re not 100% sure about what to do after you’ve read the them, then perhaps you run the risk of having spent a lot of $$$ on a product that’s not properly installed. Hence, does the floor have the ‘look’ of the price you paid? FWIW, the prep work has a lot to do with the finished job. The finished job is not necessarily relagated to the ‘look’ of the floor itself but how it’s relagated to, say, how it looks in sunlight, how it feels under you feet, how straight it is, and so on and so on. I’m sure you understand what I’m saying.
I’ve mentioned in previous posts that installing do-it-yourself laminate or engineered floors are for those folks that have confidence in their handy-person abilities. If you find yourself still a bit shakey after reading the paperwork, I suggest you find competent assistance either from a friend or a professional. Please, instead of interpreting what I’m saying as a discouragement, think of it as encouragement to be sure your new floor looks and feels like a professional job when you’re done. That’s all.
As for installing the floor over the vinyl directly, check the warranty and/or the installation instructions to be sure you don’t void the warranty. If you’re nailing the floor, obviously, you don’t want to be nailing into concrete. See where I’m headed with this? Read the paperwork (when you have it all), and if necessary, contact the retailer or mfgr with whatever you’re not sure of. Personally, w/o seeing the paperwork myself, I’m not sure what to recommend. My best to ya and if there’s more I can add, I’m able and willing.