Lift the seat up at the back and slide it backwards 30mm then lift off the bike

You will see the frame that the seat mounts onto, with 2 bolts at the back, with heads facing the front of the bike, and two bolts at the front, one on each side of the bike.

Remove these 4 bolts, they should be quite tight. It is a good idea to
remove the front, side mounted bolts first.

Once all 4 bolts are out you can remove the seat frame if you wish, or simply re-position it, down for a lower saddle, and lift it up for a higher saddle. You should only use the matching holes, i.e. the 4 lower holes, the 4 middle holes, or the 4 upper holes as a set.

Put the seat frame back on the bike and line up the holes for the seat height you require. Take care not to pinch or trap any pipes that lie underneath the seat frame.

Line up the holes for the seat height you need, and replace the 4 capheads. It’s a good idea to put them all in loosely first, then once all have been started into their threaded holes, use the allen key to tighten them up. Try and tighten them to about the same tightness that they were to undo.

Slide the seat back into position, note the tongue on the front of the saddle which should slot underneath the bar at the front of the saddle mount.

Re-fit the two bolts in the rear of the saddle that hold it onto the frame.

Re-fit the pillion saddle.

Go out for a test ride and see how it feels !