Brake fluid on firewall

OK so the factory service manual wasn't much help. How I do it... Small block of wood (2x4), drill a hole through the middle then cut it in half through the hole. Put it back together with a couple of drywall screws capturing the push rod. Block holds the piston/spool in so the master cylinder doesn't come completely apart when the rod is pulled. I have used the brake pedal as my puller ( block positioned between master cylinder and firewall ). Beware... You could damage the brake lamp switch this way. Disconnecting the 2 fluid lines was the last step.
I'm sure others have their methods too.