Need to know the model year Chevy S10.
No repairing those blower motors, replace it with a new one.
Under the hood, passenger side firewall, not far from the blower motor.
Check to see if it is getting power - if so replace motor - if not check fuse, relays and switch
The blower motor is mounted on the firewall at the passenger fender you must remove the radiator overflow tank and the ecu to remove it.
Not knowing what year S10 you have, you can generally find the blower motor high speed relay nearby the blower motor on the firewall. The resister for the other lower speeds is also found close by the blower motor.
Ain't no fixin it, you have to replace it with a new one.
1999 S10, it should be under the hood, on the firewall, on the passengers side, close to the blower motor.
First locate the resistor, it should be under the hood, on the firewall, passenger side, near the blower motor. Unplug the electrical connection, remove the small screws holding it in place then wiggle the resistor out.
You didn't mention what year S10 Blazer you have but, the blower motor speed resistor can be found under the hood, on the passenger side of the firewall, close to the blower motor.
Very Carefully
It would help to know what year you have. For an example, a 1999 S10 with no ac, the resister would be found under the hood, on the firewall, on the passenger side, close to the blower motor.
If you have no blower speeds at all, first check the fuse. If the fuse is okay I would suspect the blower speed switch and its electrical plug has melted. If the switch checks okay I would suspect the blower motor is bad. If you have high speed only, I would replace the blower motor speed resistor. If you have all lower blower speeds but no high speed, replace the high speed relay.