97 heater fan/motor replacement

[dss56]

got a 97 blazer and the blower stopped the other night would not work, took the plug off the blower resistor and got voltage to the pins while changing the speed switch. Daughter shut the passenger door and the blower started to work. Next morning not working again I pulled the connector to the blower motor and was getting 14 volts. Put plug back on and tapped on the resistor area and started to work. Went to parts store to get some brake pads and i asked what they think it might be and they said the blower motor. If this is the case how hard is it to replace, i see where the cut here line is for the motor but HOW do u get to the side near the fender and under the heater box to cut it. Is this a difficult job the tackle? winter is coming here in boston and dont want to be left out in the cold. All summer lont the motor worked for the air no this problem. What is the price for the blower motor?

thanks