You'll find out what was making the noise and smoke when you get it apart. It's not that hard to pull the unit out of the furnace. The youtube videos you found probably show how to do this.

You should replace everything, the motor, the squirrel cage blower and the capacitor. That way everything is new. If you think the blower is OK then you could probably not replace that.

The cheapest way is to order the parts online. But if you want to get it working quickly need to buy locally so have to find a source. I've bought parts from a wholesaler who sells to the HVAC contractors who is also willing to sell to the public. Depending on where you are you'll have to find a source.