Need an Android developer [Xamarin Android Native source code] to modify existing app

I have a readymade app, And need to modify basic things like:
Splash screen
Logo
Main theme colors
App & package name
And some other basic things as required.
Then after upload it to Play store and iOS Store.
[Optionally Needed basic knowledge of AWS S3 setup and AWS Security setup.]

Only Genuine Bid Please.
Please also mention that how many hour it will take to setup basic things as listed above.