I just picked up my 914/11 trans and 914 pp/fw/clutch this afternoon. I'm working on removing the gear stack this week and then flipping the ring gear. Here's another excellent resource for information ...
http://home.san.rr.com/pb914/rebuild/
This will help in removing the gear stack. When flipping the diff, I'm assuming you remove the whole diff assembly and then install it rotated 180 deg on the vertical plane ? I don't have a shop manual but is this a pic of the diff "flipped" ?
Pic from
http://home.cshore.com
I guess I will find out when I remove the side cover
Looking forward to a 5th gear !
Sandeep