It was really easy, and it the first time I did a brake master cylinder swap, so my times might be a bit longer just because I took my time and was deliberately deliberate... Just unbolt the two hard line fittings, pull the two elec. sensors from the bottom, and 4 bolts to remove the old BMC. Its a tight fit to access the lower inside bolt. I removed the air cleaner and used a long ratchet extension to get in there. Maybe 30 minutes total.
I bought an el cheapo bench bleeding kit, and it only had one proper metric fitting for my MC, so my bench bleed took a while and really didn't work all that well. Maybe 30-60 minutes.
Clean up the old brake booster and inspect for any damage or wear. Mine looked fine, and was working fine prior to the job. Some folks use this as an opportunity to upgrade their booster as well, but that's optional. Bolt the new BMC onto the brake booster, noting where any brackets or other parts were previously. Reattach the sensors and the two hard lines. You'll probably lose and spill brake fluid at this point, so make sure you've got rags for protection and cleanup.
After that bleed the lines and you're done. My wife was my assistant, and did the pumping while I watched the screws and got the old fluid out of the system. 30 - 60 minutes.
A few other pointers:
- spray all bolts, fittings and the bleeder screws with PB blaster at least a couple times leading up to the job
- clean the hardlines before removing them. You don't want dirt and grime getting into the system.
- brake fluid is nasty stuff, so take care not to spill, splatter or drip on anything with paint on it. Use tons of rags.
- they have rebuild kits out there as well, but for me it was a no brainer to just go ahead and get a new unit. Brakes are an area I try not to skimp on..
HTH.