Ok..

First off you'll need to lift the back bench seat the part you sit on then fold back the carpet a little under that you see a black cover with four bolt and wire going through the centre - you need to remove that cover under that you should then see the the top of the fuel pump with all the connectors and the fuel line to undo you'll see a large metal ring with small notches on it - you need to tap that round anticlockwise to undo so with a suitable hammer any good suitable flat end screwdriver or something with a blunt end to get it started off and then you go the rest of the way manually - also if that fuel line has a crimped clip securing the pipe then a jubilee clip can go in it place so you may need a couple at hand when you come to refit everything back - also a new tank ring seal might be something else to consider replacing too at the same time whilst your there and ensure it is seated properly around the edge of the tank opening - also before you start any work on the fuel system make sure there is no risk of any spark/is worked on in a ventilated area and the battery is fully disconnected..once the pump etc is removed then fitting is reversal of removal..making sure everything is sealed properly inc the securing ring as tight as it was before..

Hi..Sorry about that my internet went down..

However as above its just a quick release fastener - try push it down a little and then squeeze both side and with a bit of light effort pull it off - these can be a bit trouble some to get off in particular if the tank is still a little full and too because of the lack of light and not allot of room - maybe try using one these LED torches and you'll see it better - as far i recall thats usually the way they should come off - hence the reason for the non use of tools ie:- screwdriver to prise it off as once it breaks then you'll not get it to lock back in place properly - as i said they can be bit fiddly you'll just need to try as above and hopefully it will come off..