Annoyed by .rep file editing so updated spr tool. Now you can just convert spr to get dds and dat file, then open dat file with notepad++ and edit what you need, sizes are auto-calculated.
Basic usage:
1. To unpack, simply drag and drop your file.spr file onto the executable. You will result with a dds files and dat file that can be edited in Notepad++.
2. To repack, drag and drop your file.dat file onto the executable to create an file.spr file.
Download:
https://www.mediafire.com/file/ozgp89o5unih178/SPRTool.exe/file