Best way to set myself up for transition/re recruiting

Hi, I am a senior at a top target (Ivy League/Stanford/Uchicago/MIT) who will be joining a larger regional office (SF/Dallas/Chicago) of a BB(GS/JPM/MS/BAML) in their investments arm of their wealth management team (originally interned in NYC, took a regional offer due to headcount restrictions). My past couple of summers, I interned in WM and thought that was a good fit for me and what I geared my recruitment efforts toward. I was looking forward to taking this opp before the start of the summer. As a way to explore a bit, I took some more advanced finance classes in my university about PE, financial modeling etc for the first time ever and I found myself working on small side projects and developing DCFs and other valuation for fun on the side. In short, I found my interests peaked by these classes in ways that I never did in WM and heavily regret not starting IB/PE recruiting. Given I have already signed an offer and I am a senior and it is p late in the year for FT recruitment, I was wondering what steps I can take to switch into IB on an analyst level. I do not wish to reneg from the top BB that I signed my offer with. Would love to hear any tips or what I should do when I start to switch over or is my best option to aim for a T10 MBA and switch.