2000 XK8 Gas Tank
 

Need to drain about 15 Gallons of Fuel from tank .I need to put in a new fuel pump ,also any way to do this without pulling the Gas Tank? thanks for any and all help br549

If the fuel pump has failed completely draining is going to be a problem. You can try to remove the fuel filter and turn the key to see if the pump still has output, if it doesn't removing the fuel lines is the way to drain it.
In answer to you second question. You have to remove the tank to change the pump.
Follow the link below to a great step by step for changinh the fuel pump.
JagRepair.com - Jaguar Repair Information Resource

Check posts #1 #18 in the link below for cutting the parcel shelf. I did this on my 97 and it was not difficult.

https://www.jaguarforums.com/forum/x...access-118362/

Convertible or Hard-Top? I believe I recall reading that there is an access plate for the fuel pump/gauge sender under the parcel shelf in the coupe, but the convertible requires removing the tank, or at least swinging it out to a position where you can remove the pump/sender assembly. Alternatively some models have the gauge sender installed through a port on the rear of the tank which you can see when you remove the carpet/trim covering the tank. If you reckon you have 15 gallons on board then your tank must be pretty full, so siphoning will be necessary with all the usual naked flame/spark caveats if you have the option to access through the rear of the tank.

However if you have a convertible then :-

Siphoning probably still applies.

To remove the tank you will need to disconnect the fuel lines. I was dreading it but ended up using a set of Lisle fuel line disconnects (the smallest one in the set), the big craftsman screwdriver to press the disconnect into place (you can't get your hand all the way in) and a piece of ⅛" music wire with a hook on the end to pull the fuel line with. It's a fiddle, but not impossible, even with my enormous hands. There are pictures on-line showing the location above the differential that you have to get at.

Once the lines are off it all happens inside the boot/trunk. Just remember to pull the wiring harness near the bottom right (as you look into the trunk) of the tank well out of the way after you have removed the trim panels or it can get torn/cut by the seam on the tank when you pull it out.

This way wouldn't work?

Just a word of caution on the removal of the clamping ring, not wis to use a screw driver to move the ring, better to use a brass drift. You are dealing with petrol and fumes use a brass drift which will not cause sparks.
Just my 2c

br549 I used a plastic gas can spout to hold the little spring door open. I then threaded a clear plastic hose with a 1/4 in. hole into the spout and fished it into the tank. I then used a manual hand Siphon pump to get it to start draining ,let Gravity do the rest.I was able to siphon about 18 gallons out of the tank using this method. It took me about 1 hour of time to do this. Very easy to do. br549