Then -- and this is the important part -- locate a really shit bass amp. You see, the thing is, the shortcut to being in a band with no ability is to play bass in a sludge metal band. Due to the nature of said metal (and I say this as a bassist in a sludge metal band), it's all about tone. Every single part of this music is tone. It is barely about what notes you play. If you play a note that isn't D, you're going to have at least a full thirty seconds while the D you're already playing rings out to locate said note on the fretboard. You could almost bring a cheat sheet.
You'll get a lot of people saying that, to get the right sludge tone, you need a bunch of pedals and a shiny amp. Those people are charlatans, who are either trying to take your money or who have been brainwashed by someone who took their money already. You need to go on Craigslist (eBay is too reputable for this task) and search the cheap bass amps. Locate a really old amplifier around the $100 sweet spot. Ideally you'll want roughly 100 watts for $100, as $1 to 1 watt is the ideal ratio. More watts for less money, and your bass amp is unlikely to work, let's be honest. We need something that will still make a loud noise. More money for less watts, and you risk buying an amplifier that works too well.