Yes its possible. Disco's got fuel pump accessible from rear cargo area.
You will need:
- new pump (whole thing or just pump if you feel like swapping pump out. Saving you about 100$)
- two wise grip big pliers (they will help to undo securing plastic ring without breaking it)
- fillips head screwdriver (preferably power one. Would make life easier)
- two 14mm (9/16 SAE) wrenches (to undo fuel lines and hook them back)
- lots of paper towels and some cleaning solvent to clean up - there will be lots of dirt and dust around cap.
- patience. Shall not hammer around it - tank is plastic.
Overall operation if you replacing pump with new assembly is about 15-20 minutes (i did it in darkness, in cold evening last time in 15 mins). If you replacing pump only - about 30 mins.