Ready made app customization

I have a ready-made mobile app completed code and script, with a license I would like to customize this mobile app with ( Name, logo, background layout ) I have already done, name, firebase account, page name color change and log change when I generate apk the size shows 122MB so I need a high skill developer to fixed my logo again and generate apk with a small size to work because that 122MB I have try to install that show crashed, for more detail, i can explain on chat Visual studio i have already installed in high power server i just need to give you access developer will check there and fix the issue
it used C sharp technology