In... not tested it out yet, later on... Not a guide, just a few pics I took on the way through, there are proper guides out there.
Assembling is easy, just take apart the old part, pull out the plunger part, and assemble using instructions with GFB part, making sure to oil piston. My DV was/is a rev G, and had no splits, I'm still happy to have changed it, should def be able to tell if there is difference! Gonna stick it in the for sales and see if someone wants it.
As far as fitting, I would advise taking off engine cover as this isn't hard and you get a bit more room to push things out the way.
I started to undo the circled bolt (below pic) then realised that's not part of the DV so don't bother! The far bolt is a little tricky, so best to use an extension or two on your ratchet (I used a mini ratchet), torx out, hex back in. be careful of the stock yellow o-ring, it is brittle (well mine was) and the jigging and poking about to get the DV seated again does tend to loosen the clicked in position of the GFB part to the stock DV body which unseats the o-ring and makes it easy to snag and slice it. Also be careful of the far bolt, very easy to drop when trying to locate it in the hole (I did try locating it first, then seating the DV, then doing up the two near bolts, but this generally unseated the GFB part from the body and I had to start again.) Eventually got it in by doing the two nearest bolts, then pushing that pipe you can see above the red circle and squeezing the third bolt in and tightening by hand, then ratchet.
Fitting difficulty rating for a novice driveway "mechanic" -
6/10 (just because of the far bolt position, smaller hands may make it easier!)
If you take the engine cover off, you can change the air filter too, I did... yuk!
Hope this helps anyone new to it this stuff like me, first mod! Getting petrol later so am going to get it warmed and give it a blast to see if I notice any difference!