My drivers seat wont go up,its stuck in the down position

does anyone have any tips please ?
Is it ...
1 : spray with wd40
2 : hit with F.B.H
3 : replace cus its f*^$ed
or none of the above .
this is the cdi seat and was like this when i got it,its not just stopped working.
So it's been seized for a while then.........
DO NOT
- Yank on the lever arm - you will break it and then the seat height adjuster is irrepairable
So
Undo the seat and remove it from the car (4 allen bolts)
Turn upside down on a suitable surface to protect the seat
Get plastic bag and section to prevent oil/wd40 from sinking into the seat foam and fabric
Lubricate every moving (or in this case non moving) lever fulcrum and pin with wd40 or similar light oil
Leave to stand to let it do it's work
Invert the seat and place in a stable base surface
IMPORTANT - when adjusting seat height the system needs a body on the seat to act as a counterbalance - never attempt to raise or lower a seat without sitting in it
Sit on seat and gently try to work the lever - do not be agressive with it the mechanism has to be freed off gently or you will snap the lever arm
DO NOT
- Use stilsons/mole grips on the shaft that runs under the seat - it's hollow!!!!
If it doesn't move when you first try it leave it the right way up so the oil can go the other way.
If all this effort still fails then it's new seat base time - plenty about so no worries but I've only had it not work once.