Help a newbie out?

Hi everyone,

First of all I hope I'm writing this in the right place. I never used a forum before I've also never modded a game before so I have some questions!

I found a custom texture for a different Leon skin/costume? however it was made for gamecube version of the game that this person plays via an emulator (god I hope I'm explaining this right. I barely understand this), I however have RE4 bought on Steam for my PC. From what I understand that means I have the UHD? They said that the texture is pretty small, so it might not hold up for UHD, but I'm interested in trying.

I've read a few posts on here and if I understand things correctly, in order to mod anything I need to get a tool to unpack files from the ImagePackHD folder, then find the right texture in there - the one I want to change. So for me that would be Leon's outfit? Then I have to open it in Photoshop and make the changes I want, and repack the file. Or alternatively I could delete that texture, replace it with the one this person made, repack and see if it's not too small and if it works? Their files are just pngs tho, so I don't know if I wouldn't have to convert them first somehow.

Am I on the right track in any sense? If any of you can link me to threads that you think might be helpful, or clear somethings up, recommend what tool to use to unpack said folders etc I would be super grateful!! And I'm sorry if this is just a confusing mess, I'm really  out of my comfort zone here

(Also I'm not posting any links to that texture just bc I don't know how the person who made it would feel about it)