you will also have to repackage the client with an installer. Are you capable of doing this?
The images are in spark.jar. This can be unpacked with Winrar and the jar itself can be updated with winrar too. The images are located in an folder named “images”.
Please look through the forum, there is a document (I think by church) describing the change procedure.
I am not a programer so i dont know how and what too unpackcan and repack, so can you provide us with documentation link so that i can go throuch and do the needfull.