I used the Destroyer and my Textbook along with all the notes i take in class. I save my notes just in case for times like this. It took me about 1 month to re-learn and have a good grasp of GChem and OChem. On average it takes me about 1 week to relearn the subject and then have a good grasp.
Bio is my weakest subject so i just had to read my bio book and go over as many questions as i could. From Destroyer and Kaplan. I also recently took Anotomy and Physiology 1 & 2 which really helped me in the bio section and knowing it.
Quantitative Reasoning, well i'm a Mathematics-BS major and really didn't have to do anything in this section except problems. I went straight to the Destroyer and Kaplan books to do problems. Yes i did get some wrong and some took me longer then others, but that needs to be improved with practice and time, and i have noticed an improve in my speed and accuracy of doing problems.