Removing seized pedal off crank

If right-hand crank, crank at about 2 o'clock position, spanner at about 10 o'clock position.
If left-hand crank, crank at about 10 o'clock position, spanner at about 2 o'clock position.

Add big leverage e.g. scaffold pole. Push lever down.

If only it was that easy. It's the non drive side crank, the drive side came off piss easy - I put all 16stone of my weight over it too