Had the same. answer is remove the bottom of the tray rubber mat, you will find a trap door very stiff to open but it will if you give it enough wellie, and behold the adjusting nut! In order to move the bloody thing was another matter, had to purchase a 12mm cranked ratchet spanner to do the job. Tip put 8 clicks on the handbrake lever before you adjust or you could have the shoes binding. Do not go for leas than 6/8 clicks to set the brake. When in drive they should hold you.