Thought I'd share my experience 
Decided to give this a go after chasing an annoying whistle I thought was the alternator. Odd idle and jerky cruising at 30 (surgy) and a few YouTube diagnostic research vids led me to it being number 1 suspect.
I put around 12 hours into it, not wanting to remove to much and reading others had done it without removing anything else I dug in with no quit.
I can confirm it is possible. Would love to know how much a garage would charge for the job though as I'm mentally damaged for life. I used to own a classic mini so used to jobs in tight spaces, this is on a whole new level for access.
Car is transformed now so a very happy owner again, albeit bruised cut and struggled to walk for 2 days due to my knees being in a stress position for so long
. Why is there a sticky out thing on the bulkhead right in line with the back of your hand? 
If you know someone with child's hands and the strength of an ox it'll be easy.
Just put it in the garage