Regards the fuel filter, I originally ordered one from ECP and it was the short one without the drainer at the bottom. I decided to send that back and just pickup an OEM part from SEAT which was the taller one with a drainer. I doubt it makes much difference but for the sake of a few quid, i went official
The connections on the filter - there are directional arrows on the pipes and etched on the top of the filter (or at least should me). Slightly different to what you described, the following is what I did,
-Pull out butterfly clip and keep somewhere safe
-Lift that part out the filter (remember to change rummer grommets, one is thinner than the other, remember to keep them in the right places with replacements. Think one was blue the other was black)
-Use mole grips or pliers to open the small metal clamps and just simply move them up the tube a little.
-Ease off the cable by pulling, twisting and eventually it will come off - have a rag at the ready as some diesel may come out !
-I wrap the tubes in kitchen towel while I lift the filter out
-Swap out filters
do the same in reverse to put back !
If its a cleaning exercise then you wont need to replace the rubber seals and just drain off the filter and put it back in and connect up.
I personally leave the engine running for a few mins after as remember, there is no fuel in the filter - I let the system sort itself out for abit
Remember there are are 3 or 4 little black hooks that hang over the edge of the filter to hold it in.
Cheers
-Stu