Pretty easy. Remove rear wheel, rear shock. Undo the clutch line at the handlebar reservoir and cut the cable ties that hold the clutch line to the frame.
Undo the three bolts that hold the slave cylinder in place, wriggle and contort the slave to extract it through the gap between the subframe and gearbox bar (it will go through, quiet easy once you';ve done a few and got the knack.
Undo the two small banjo bolts that hold the lines to the slave.
Attach the rear banjo of the new hose to reservoir banjo of the old hose (cable tie through the two ends) and pull the old hose through from the slave end until the new hose is in place, cut the cable tie joining them.
Attach slave cylinder and bleed hose to the slave, wriggle it back in place and screw the three screws back in place attaching it to the gearbox. Then bleed the system
I actually bleed the unit before fitting the slave back in place, there is enough slack in the hose if you undo the top left 14mm fork nut push down the stanchion and let the hose sit "this side" of the fork stanchion so you have loads of slack, bleed the unit, refit the slave, put the hose back the other side of the stanchion and do up the 14mm nut . tickety boo all done.
Less than an hour if you've done it before.