open up 4 bolts M8 to take the entire pedal into the cab. Use the space you've got to release the oil lines and bolt the cylinder off the back of the pedal baseplate.
remount in reversed order.
Some folks found it handier to open the hood, remove the front panel of the cab, between hood and cab, and enter from there.
It was a couple of years ago that i did all 3 masters of the 5245, but i do remember taking off and remounting the oil lines had to be done one by one while shoving the assembly into the hole in 2 steps, mounting 1 brake line at a time. it was a 1.5 hour job, including an hour of figuring out how to tackle the job