How do you adjust the timer volume on a stoves 61GDO Gas cooker

SOURCE: Lost handbook for cooker. Cant remember which

There are five buttons on the clock panel and from left to right they are:- Minute Minder, Cook time, Ready Time, Plus and Minus.
TO SET THE TIME OF DAY
Press the Cook Time button and the Ready Time button simultaneously. Use the Plus and Minus buttons to set the time.(24hr clock).
TO SELECT AN ALARM TONE.
Press the Minus button to listen to the first tone. Release it and press it again to listen to the second tone etc (3 tones)
Releasing the button after the tone has sounded will automatically set that tone.
SETTING THE MINUTE MINDER.
Press the Minuter Minder button and either the Plus or Minus buttons simultaneously to set the time.
You can cancel the timer at any time by setting it back to 00.00 by using the Minus button.
After setting, the display will revert to the time of day, but by pressing the Minute Minder button again, the display will show the remianing time.
If you want all the information, then it is best if you supply a vaild email address and this will give you access to my BT Digital Vault, where you can have a complete copy of the handbook that I have scanned in.

SOURCE: Replace seal on Stoves 61GDO,

444445572 Gas double oven - stainless
http://www.espares.co.uk/parts/cookers-and-hobs/stoves/444445572/p/1092/630/0/914923
It has two different seals on that website, but I think It'll be obvious to you which one you'll need.

SOURCE: how do i increase the

From the handbook:--
Press the MINUS button to listen to the first tone.
Release the MINUS button and press it again to listen to the second tone.
Releasing the MINUS button after the tone has sounded will automatically select that tone.