Quite a few have this issue and I'd say it's mainly because they are not being "robust" enough with it.
- Sit on the seat.
- Pull the right hand lower handle all the way. It will stop about an inch before "all the way". Pull it harder. Your fingers will break before the handle.
- Then just walk, heave or pull the seat forward on the rails. Once you have pulled the lever fully it completely disengages the mechanism and is easy to move. At the first stop it will move, but not well as the ratchet is still semi engaged.
- Take it all the way forward - to the very end
- Drop the headrests
- Give the middle strap a good yank. Pull it fully out, again, until it pulls no more.
- Push the seat back until the back is fully down.
- Then pull the handle all the way again and push the seat back until the gap is closed.
- Job done.