Transmission Fault??
 

so I just recently bought a 2006 RR and already its spitting up a transmission fault, code P0735 (improper 5th gear ratio). I've already done a little digging and found out that it could be the solenoids so I'm just going to do myself a favor and go ahead and replace them as well as the transmission fluid. any advice on where to go from there of if I'm even going in the right direction?? I want to get this car back to 100% as soon as possible!