Serial input manipulation


I need to display a live weight reading that I'm receiving through a HC-06 Bluetooth device.
I can see the data but its show as a continuous stream that looks like one long string.

Displayed in a text box it looks like this:
It behaves like a FIFO table

If I apply weight:

The values are signed aswell:

How do I manipulate this input to display "23 kg" or "-1 kg" (ignoring the unnecessary 0s)

Please download and post each of those event block(s)/procedures here ...
(sample video)