04 Outback Drive Side Window Mechanism - Busted

The driver's side window on my 04 outback doesn't go up and down properly. It appears to be misaligned, and when it gets within about 2 inches of closed, gears chatter and it stops moving. Controls seem to work, as does motor. Questions: 1) Does it make sense to avoid the cost of poking around in there and just replace the scissor mechanism the raises and lowers the winder, or could it be something I'm missing and 2) is this something I could reasonably do myself (or is it one of those ongodly chores one would only wish upong a subaru dealership mechanic).