It is possible, this method works for some other games. Just try it.

There are no tools for that. You can edit by hex editor or download unreal engine devkit, make your own uexp files and figure out file format to edit them.

PVRTexTool Download: https://community.imgtec.com/downloads/ ... k-2018-r1/

As you can see, there is message "please insert the content for the variable KEY:"
You have 13 keys implemented inside this script, so if you are lucky one of them should be the right one. Just type the number of the key, for example "5".

There are some tutorials about that. For example https://www.youtube.com/watch?v=xZONf5fXEOg

It is also good idea to read quickbms readme http://aluigi.altervista.org/papers/quickbms.txt
In section 3 you have information about reimporting.

Maybe reimport option for this script will work fine http://aluigi.org/bms/unreal_tournament_4.bms

Only by packing everything to pak file.

You could try to export GFX file using hex editor, edit and save it in jpexs decompiller (this tool can edit GFX files when they have right file structure) and then import file to UGX by hex editor. But you have to be careful with GFX file size, it has to be the same as original.

Maybe this topic will help a little. Archive seems to have very similar structure in MLB The Show 14
http://www.ww.zenhax.com/viewtopic.php?t=3764

Use TextureFinder: viewtopic.php?f=33&t=15540

Use MPQ Editor http://www.zezula.net/en/mpq/download.html

Such conversion may be not possible, but maybe this will help: https://www.se7ensins.com/forums/threads/help-patching-dll-onto-xex.1197914/ https://www.se7ensins.com/forums/threads/release-tu23-dll-loader.1003168/ https://www.se7ensins.com/forums/threads/load-dlls-without-a-patched-xex.1645603/ http...

Try these tools:
http://l2devsadmins.net/l2devsAdmins2-0 ... pic=8684.0
https://sites.google.com/site/l2clientmod/l2tool
http://l2rr.ucoz.ru/load/programmy/5-5

Try to use GIMP with DDS plugin.