I will have to send quite a lot of numerical data in the form of integers
"quite a lot" is not a very accurate definition of the quantity of data. The actual number of integers per second would be a much more useful quantity to know.
What is the most painless way of doing it?
The most painless way and the best way are not necessarily the same way. Whether the most painless way will be satisfactory is not known, since the quantity of data is not known. Nor is the application that is to receive the data.
Do I have to split the data into words and bytes
Only Microsoft has a data unit called a word. No one else (in their right mind) does. So, no, you don't have a break a 2 byte integer into a two byte word before you split it into bytes.
You may not need to split it into bytes. You may be able to send the data as strings. It all depends on the quantity of data being sent, and the receiving application.