The key is to focused on expanding your vocabulary in the textbooks from primary 5 to 6, you not only can pass paper 2, you can pass the whole paper too!
Paper2 : 50/90 assume comprehension 0/40
Paper 1: 22/40 assume your compo is average
Paper 3 oral : 25/50 as in just pass
paper 3 LC: 10/20 as in just pass too
Total is 107/200 which about 53.5% = AL6 = PASSSSSSSS!
So passing PSLE Chinese is really simple math!
BTW 45% is already AL6, its a no brainer.