More than 2 hours.
You will have to remove the transmission pan, and then the valve body. The solenoid back is under all that. The valve body has about 17 bolts holding it in.   This can all be done with the transmission in the car still, but I suggest doing it on a lift. In these instances, you must replace the solenoid pack. REPLACEMENT COST for a Transmission Shift Solenoid The cost for transmission solenoid replacement depends heavily on the type of vehicle you drive. For example, a single transmission shift solenoid can cost anywhere from $15 to $100. A solenoid pack, which includes all the solenoids for a particular vehicle/transmission can cost from $65 to several hundred dollars or more. Remove the starter from the car. If it’s a tight squeeze, and it often is, remove the support bracket (if there is one) before you get the starter out of the engine bay. Depending on your car, you may have to disconnect or remove adjacent parts before you can get the starter out. In this article, I'll show you how to test the transmission shift solenoids (specifically 1-2 solenoid and 2-3 solenoid) on your GM 4.3L, 5.0L, 5.7L pick up, van, SUV. You'll be surprised just how easy it is to diagnose these shift solenoids when they have failed. REPAIR INFORMATION for a Faulty Shift Solenoid Once it is determined that you have a failed transmission shift solenoid the only repair is to replace the faulty part. Replacing a transmission shift solenoid can be done by most any auto repair shop, automobile dealership service center or you can do-it-yourself DIY. Remove the battery ground. Now you can go below and remove the wires to the starter. There will be a fat wire from the battery or, if your car uses one, an external solenoid. There will also be one smaller wire, either a ring lug on a stud or a spade lug, from the ignition key. Oftentimes, replacing a transmission solenoid will take no more than 2 hours, and repair shops on average charge $60 to $100 per hour for labor, not including cost of parts (a replacement solenoid should cost you no more than $200) or shop fees. Transmission fluid is directed throughout the valve body by various transmission solenoids– such as the transmission shift solenoid, lockup solenoid, or transmission control solenoid (there’s also a torque converter clutch solenoid) –that either open or close hydraulic valves to regulate fluid flow.
http://www.answers.com/Q/How_long_will_it_take_to_replace_a_transmission_solenoid_pack_on_a_2003_dodge_neon http://myautomatictransmission.com/automatic-transmission-solenoids.htm http://www.wikihow.com/Replace-a-Starter-Solenoid http://troubleshootmyvehicle.com/gm/4.3L-5.0L-5.7L/automatic-transmission-shift-solenoid-tests-1 http://myautomatictransmission.com/automatic-transmission-solenoids.htm http://www.popularmechanics.com/cars/how-to/a5837/how-to-replace-a-cars-starter-motor/ http://transmissionrepairguy.com/transmission-solenoid/ http://transmissionrepairguy.com/transmission-solenoid/
how long to change solenoid