Outline a how-to script paced for people actually following along, not just watching

You are outlining a how-to or tutorial video script paced for a viewer who is actually trying to follow along and do the thing, not just watch passively. A tutorial script that reads well as narration can still fail its actual audience if it never gives someone doing the task in real time a moment to catch up, which is a different failure than a boring or unclear explanation.

TASK BEING TAUGHT
Replacing a bicycle chain and adjusting the derailleur afterward

VIEWER SKILL LEVEL
Complete beginner — has never used bike tools before, may not own a chain tool yet

MATERIALS OR TOOLS REQUIRED
New chain sized to the bike, a chain tool, a small screwdriver, gloves recommended

KNOWN TRICKY STEPS
Getting the new chain length exactly right (too many or too few links is the most common beginner mistake), and reconnecting the chain without the connector pin popping out under tension

TARGET LENGTH
10-13 minutes

OUTLINE RULES
Open by stating the full materials or tools list and the total time commitment before any instruction begins — a viewer deciding whether to follow along right now needs that information upfront, not discovered piecemeal as each tool is introduced mid-step, which forces someone already mid-task to pause and go find something they didn't know they'd need. Break the task into discrete numbered steps matched to natural stopping points in the actual physical or digital process, not to arbitrary time chunks — a step boundary should fall where a real person doing this would naturally look up from the task to check they're still on track, not wherever happens to be a clean two-minute mark. For any step flagged as tricky, slow the pacing specifically there: state the common mistake explicitly before it happens, not only how to do it correctly, since a viewer who doesn't know a mistake is common won't know to be careful at the one point where care actually matters. Build in an explicit verbal checkpoint after any step a viewer would need real time to complete alongside the video, not just watch — "pause here if you need to, this next part assumes the last step is done" — rather than assuming a viewer will manage their own pacing by scrubbing the video themselves, since most viewers won't. State results or symptoms of getting a step wrong, where relevant, so a viewer who's fallen behind or made a mistake has a way to self-diagnose rather than only discovering something's wrong at the very end. Do not front- or back-load all the tricky content — if there are multiple genuinely hard steps, each one gets its own slowdown and explicit mistake-warning in place, not just the first one encountered.

OUTPUT FORMAT
1. Materials/tools and total time, stated as a single upfront block.
2. Numbered steps, each with an estimated timestamp, the instruction, and — for any step matching a tricky step provided — the specific common mistake called out before the instruction.
3. Explicit checkpoint lines marked clearly, placed after any step requiring real hands-on time.
4. A closing troubleshooting note listing symptoms of the most likely things to go wrong and what they indicate.