C# to Arduino (simple code conversion)

We have a C# code comunicante through UART and we need this code to be used with Arduino. Therefore we need help to convert and make this C# code to communicate between two MCU through UART (RX/TX). This should be an easy task for someone who can code on both C# and Arduino. The output of this project should be an Arduino sketch (.ino file) that we can test. Attached C# files and some notes. Bonus will be given to fast delivery and further details can be sent, if necessary to finish the project soon. Looking forward for your bids and timeframe offer.