Final Fantasy Hacktics

Hey yall i am very new to changing FFT but it is my favorite game, ever. I always do my run with 2 normal units that I always name my favorite names and take them through the whole run. I thought it would be really fun to change their appearance with custom sprites so they have the look i imagined in my mind as i do my playthrough. However as i followed a few guides on editing sprites i hit a wall. I am unable to import my UNIT.BIN, WLDFACE.BIN, and WLDFACE4.BIN into the CDmage files. When i right click the import isn't an option and i followed all the other steps to the T to ensure I should be set to go. Its the last step and I'm worried I might be unable to edit the game. I am using a modded version of the game which is The Lion War mod. Please let me know if this has happened to anyone else. Thank you.