Hi guys. About a year ago my tranny went out. The shop said it was the shifter solenoid. The tranny would only stay in first gear, and would never shift up. Reverse would work, but when it was in drive, it would only stay in first. So I would assume the shop is right? My question is how hard is it to replace it? Is it even something I can do on my own? Or does it require special tools. Any help would be great. Thanks..