Ok, you start with untightening the top vertically facing bolt. This will relieve the pressure, so you need to slacken it off slowly... And expect an amount of leakage. I'd just slacken it off, let a bit seep out, then lock it off again whilst the spill evaporated. I put a rag underneath to catch any spills. Just do this several times until there is no more leakage.
Also, you'll notice on the existing and new filters that they both have hex head connections. You'll need to use these as with putting the amount of pressure you need to undo and tighten the connections, you stand a very good chance of sheering them off.
Once you've drained as much of the fuel as you can, undo the horizontal connection (Again using 2 spanners). And again, expect more leakage. So follow the same procedure as before.
Once both connections have been drained it's time to remove the filter. Follow the pipe work of both connections and undo both the first brackets securing them to the bulkhead. This will allow you a bit of freedom and to move the pipe connections away from the filter (but still be careful not to bend the pipe work too much). And also beware of lowering the pipe ends as there is obviously still excess fuel in them that will pour out
Then undo the fuel filter bracket. There's 4 bolts total... 2 clamping the two halves of the bracket together, and 2 bolting the bracket down to the engine bay. Undo which ever you find easiest in order to remove the filter. I unscrewed the bracket from the engine bay first. Again, remember there is still excess fuel inside.
Once the filter is removed, it's simply a case of reversing the process.
Two tips for you though...
1st, although the connections came out quite easily, they can be a bit of a pain relocating the threads due to the angle. So before you clamp down the new filter, put all the bolts, bracket and filter in place, but don't tighten any of the bolts. This should give you enough play to screw in the connections the first couple of threads. Then clamp the filter in place with all 4 bolts (Remember there's a lip on the bracket that hooks over the top of the filter) and then tighten the connections... Again using 2 spanners for each.
2nd tip, this may not apply to all filters, but I found that before I actually fitted it I found mine was getting sticky in my hand
It turned out to be the fuel I had on my hand was eating the paint from my filter 
So rather than it looking pap, I decided to remove the rest of the paint (at least from the top, where it was missing anyway) I used the remaining fuel from the old filter to do this Looks a lot better for this 
And voila!
After all the bolts and connections are back in play, start her up to make sure she works and there's no leaks. Obviously she may not start immediately the first time, but do not fear 
