Well eventually got around to tackling lifting the tank, disconnecting the quick release fuel line and changing the oil pressure sensor.
It actually went pretty well, maybe just lucky.
This is how I done it and it may be of some help to someone else!
1. Take off side wings with Guzzi badge on them, on the right hand side you will then be able to see the electrical connection plug for the fuel pump. Disconnect this and then try and start the engine (it wont start) for 3 or 4 seconds as this will relieve the pressure in the fuel line.[You must be registered and logged in to see this image.]
2. Lift the seat and pull main fuse and disconnect the battery and remove. You can then remove the two lower bolts holding down the tank, also undo the drain hose from battery compartment. Then undo and remove the two upper bolts holding the tank at the ignition switch.
3.Gently lift the tank a few inches at the top and slide a piece of timber underneath, then do the same at the bottom of the tank, you can see how much timber I used in photo.
Then undo the drain from tank overflow at bottom of tank.[You must be registered and logged in to see this image.]
4. You can now reach in to disconnect the fuel line quick release coupler. I found that if I stood on the right hand side of the bike (as you sit on it) and reach in with your right hand and grab the grey connector while at the same time reaching across the tank and coming in from the other side with your left hand to catch the red elbow you get a good grip to loosen the coupler. I just pulled back on the grey coupler and off she came without any great bother. I MAY HAVE JUST BEEN LUCKY [You must be registered and logged in to see this image.]
5. Remove the tank and support it safely on some timber on a bench so as to keep the red plastic elbow from having any weight on it.
I then blew out any dust and crap that was resting in the engine V. I disconnected the electrical connection from the Oil Pressure Sensor and removed it using a spanner.[You must be registered and logged in to see this image.]
6. I replaced the oil pressure sensor with one that is used in a BMW car. I put everything back together carefully and took her for a spin, Everything seems fine and the dreaded Service Triangle with the red oil can, hasn't appeared as of yet
7. Then I got a rush of blood and checked the valve clearances, balanced the TB,s reset the TPS and changed the oil +filter. Running Great
I hope this was of some help to others as I have gotten a lot of information and help from people on the site. Keep her lit,