Toby (Sasquatch on here) has a video on disassembly and tune up of the pony pinion clutch and brake.
Like Hector said, I have found that draining the old oil and refilling with any brand of ATF will make braking the pinion and engaging the gear without grinding a LOT easier! The thinner fluid causes less drag between the disks of the disengaged clutch and it's just not as slick as a motor oil, which helps the brake work better. Finally, you probably won't need to run the clutch adjusted as tight. I find that any discernable "snap" when your engaging the clutch is tight enough and it will turn the main engine just fine.