Good news for you: I worked out how you can change to a style of any length of the name:
The problem is, that there seem to be some pointers and stuff like this.
Well, let's assume you want to change from StyleA.sty to OtherStyleB.sty, your level file has a size of 15997 bytes (which is 3E7D in hexadecimal).
Firstly, change the style name at the obvious position. Note to insert the missing bytes, not overwrite the "0x00"s following.
Then, change the byte before the style name to the size of the new name + 1, for the example, to 0x10 (cuz it's 15 bytes long).
The first four bytes in the file mean the file size (lowest valued byte first, i.e. your file is now 16002 bytes long = 3E82 hex, so change it to 0x823E0000).
Then there are the file size once again and pointers in the last 28 bytes, one takes four bytes (again, lowest valued byte first). Adjust the file size again, and change the value of the pointers by the value you change the file size (for the example, +5), excexpt for the third of the pointers (0x22) because it points to a place before the level name and therefore is not shifted.
My explaining skill are not good, but I hope you understand what I want to say.
