First took it to a friend to replace the slave cylinder. That cost $400 and it was fixed initially, however the line between the master and slave cylinders (the pedal and the transmission) was mysteriously broken and leaking, which ruined the master cylinder. Took it to a mechanic to replace the line, then found the master cylinder needed replacing. After a year and a half it's finally fixed.

The slave cylinder is inside the transmission which means you have to pull it out. The line between the master and slave cylinder also requires a special tool, making this a difficult at-home repair. The master cylinder is easy to replace if you are relatively good at making repairs.