To fly another cathegory of aircraft, e.g. SEP or TMG, you will need to get the classrating entered in your licence. Each classrating requires a training and an examination.
License / Medical:
PPL(A), LAPL(A), CPL(A) or ATPL(A)
valid aviation medical certificate (Medical)
The theoretical training will give you an introduction to the aircraft class to which you’d like to extend your licence. For TMG, e.g. engine off procedures and approaches in gliding configuration.
The classrating course requires a minimum of 3h flight instruction on the new aircraft class. This compromises mostly airwork and patterns to get you familiar with the new aircraft category.
Each classrating requires an examination. There is only a skill test including an oral questionaire of the theoretical knowledge.