Hi,
I removed the drums and bass using Izotope RX, then added my own. You can do that with any program that has stem separation (Cubase added the option in v15). I also doubled some existing sounds with my own to give them more definition, and added a couple of lines. When I don't have access to the original stems (as is usually the case), that is what I do. Also if I call it a "bootleg", as in this track, it means I have not changed much. If I call it a "remix", then I've done more stuff.