Hi! I know this was posted a while ago, but I thought I'd give my two cents since I was in the same situation. I originally took my MCAT Sept. 2021 and got a 516 (131/127/129/129). I retook it this past May after almost 3 gap years because this first score expired and got a 523 (129/130/132/132). The way I approached studying was heavily emphasizing content review. Like you, there was a lot I didn't remember anymore, and I reasoned that I can't answer a question if I don't have the foundational knowledge. So I probably spent about 3 months on/off reviewing my Kaplan books that I had used for my first test. From what I can tell, the content of prep books don't change, just how they're organized, so you don't need 2026 MCAT review books to do well. I also used the MilesDown Anki deck to help with long term retention of the content. What I think made the biggest difference though was UWorld. Super expensive for sure, but really helped with building up my test endurance and just practicing applying knowledge to passage-based questions. I used it only for the last 2 weeks before my test (I'm a GREAT procrastinator lol), but I believe the increase in my CARS score is due to UWorld. I practiced half or full sections of CARS everyday depending on what else I was studying, and it helped a lot with my timing and reading comprehension/extrapolation from the text. Also, I think UWorld helped a lot with practicing how to understand the studies in bio/biochem/psych passages, which are often dense and complicated, and I eventually learned how to break down these studies, focus on the main results, and interpret graphs & tables really well after some practice. On Test Day, there wasn't a single section where I ran out of time to answer questions (I even had leftover time to go back and check answers for each section), and I think slamming UWorld questions was the reason for this. I only took 1 full-length practice test (scored a 519) the week before my real test because I felt confident in my endurance/timing, but I would honestly recommend taking more and at regular intervals to get a feel of trends/weaknesses to address. I just got burnt out and didn't want to give any more money to the AAMC lmao. In general, I think most study advice still stands for taking the MCAT even after gap years. I would just make sure you invest time in a solid foundation of the content.
In regards to your question about changes to the exam, I didn't feel like there was a big difference between my first and second test, but I honestly don't remember much about my first test lol. I would say that the high-yield concepts, like amino acids, still hold up even now, so I wouldn't count them out.
I won't lie, it was a BRUTAL four months of studying and I did reschedule my test to one week later to give myself more time to study (RIP to my bank account cause that rescheduling fee is a CRIME), but it was definitely worth it so that I could apply with a really strong score.
Feel free to reply here or DM me if you'd like more info!
TLDR: really focus on content review, especially for high-yield stuff; use Anki or something similar to help with retention; UWorld was a great resource to revive my test-taking skills, especially in terms of timing, and was a godsend for CARS in particular; to my knowledge, the content of the test is still the same, especially in regards to high-yield concepts
