We're just not into plastic disposable markers because we can't justify creating forever lasting plastic garbage for making things like bake sale signs, solar system projects, or student council posters.
Yes it helps to possess fine motor skills and a modicum of patience for these. This is old school stuff.
Pull back the string - but NOT TOO MUCH - then gently unwind the paper to reveal the waxy color "lead". If you rush it, you'll end up tearing the paper off too soon, and then you'll have to pull the string again and start all over - Whatever, it's not a crisis, just take your time and you'll get the hang of it.
Now, we also carry the Caran D'Ache Wax Pastels - Kind of a fancy pants version of these without the string or the peeling - but they're not inexpensive either, so there's that.
We love them both - different tools for different projects - that's how we see it.