If you’re going to use the chain whip you just made, you’ll also need a way to get that cassette off. A lockring remover is a must-have; unless you use one of the shady removal methods I’ve seen on the internet—which I wouldn’t necessarily recommend unless you don’t care much about the condition of the wheel after you use them. I recommend Park Tool’s iterations here that cost about $6, but you’ll need to buy the specific one for your brand/type of cassette. (By the way, I’m assuming you already have an adjustable wrench laying around somewhere to use with this tool. If you don’t, well, you’ll need one of those too.)
I brought my bike into Kyle's shop to fix the noise in my rear wheel. The mechanic suggested that I need to overhauled the rear hub for $30. The next day the noise came back even worst. I brought it back to the shop and they said it was the freewheel driver not the hub that needed to be work on and it would cost me extra $30 to overhauled it again plus the part to fix it. At this point I walked out of the shop and took my bike to David's world. The mechanic at David's world took a quick look at the rear hub and indicated that the axle was put back too tight when Kyle's mechanics were working on it and further identify the issue. I ended up paying David's world the $30 plus part to fix my bike, but the major different is that David's World has 30 Days services warranty claim. If you have any issue with your bike within the 30 days the service was performed you can bring it back and they will fix it no question ask.
Friction gear systems are a lot simpler to adjust, because the movement of the derailer cable can be modulated as you ride, every time you change the gear- they require less cycle maintenance. Modern index shifting systems are a little more complicated because each ‘click’ must release the exact right amount of cable to allow the derailer to move the correct distance to move the chain from one gear to another. Setting up and adjusting a derailer is not difficult and requires only basic tools, but there is a methodical procedure to follow.