Lenk / rest periods split up.

Hello to all professionals here. have a kinky problem regarding the steering and rest time distribution. I have to make a move with a rental truck (7.5 to.) with digital speedo (pronounces a driver card is created for me) I have pure driving time on the distance ( 920km) we say 12h because I normally do not drive freight, so otherwise NO driving times run up with me, I can drive the first day immediately with 4.5h , 45min. break, 4.5h start. So I still have one st and the rest on it. The following day rest time I would split into 2 parts, first 3h then I could make the rest travel time, which I still lack (because I get in 10h only about 800km far, and no 920… hihi..) and then I would turn off the vehicle for 9h. (driver card remains in it…) For the return trip I would do the same. Is this so legally in order, or do I have a mistake in thinking ? would be good if someone (..who knows) could give me a tip there. nnn.