Hayter 41 619E autodrive.

I have lost the drive to the roller on this mower. From web searches it appears that the belt needs replacing. Chain drive to roller is ok.
Can anyone tell me how to get at the belt, or direct me to some written instructions. Parts diagrams do not help enough. Reasonably competent and have necessary tools.

Sorry to be long time in replying and thanks for your post.
My mower was a Hayter Spirit 41 autodrive. After research found that belt breaking was a common problem. general reviews were poor.
Mower was too fast and no way to regulate the speed. Slipping the belt to slow it down led to belt failure.
Have now bought a better mower, Hayter Harrier 48 with proper variable speed and slow enough for me to keep up with. Now too wet to use it|