Roller legally throttle at 45km/h – TÜV ?

Hello, since Tuesday I am also proud owner of a driver’s license (BF17) and now wanted to make my TGB Bullet RR faster. On the one hand, an acquaintance said that he had to pay more than 300€ for his TGB, so that he drives 45km/h and comes through the TÜV. Friends of me claim that I can do it myself or have it done in a workshop and as long as my scooter was changed to 45km/h with the insurance, everything would be fine with a police control (Ro ller is in the original condition, never changed anything), because I would have insured him and have the driver’s license. Before I do anything, I wanted to know exactly how I should handle it. Buying a new scooter is a bit stressful, because I would have to sell the old (newly bought) and next week another oral exam is due 👿 . MFG Jonny