I'm a long time 2k Fan but since I play on PC and the downloads are currently not working for me I have decided to give modding a shot. In the past I've played myLeague with a couple of friends where we manage custom franchises, normally we just upload designs and download them for our teams. However 2k is having issues resolving the downloads issue from what I've gathered.
Question: How do I replace the expansion teams already in the game ie San Diego Surf, Baltimore Barons etc and upload my custom team designs? I've noticed the game also has other decals when you go into the edit menus, is there a way to replace those too?
What downloads/plug ins would I need? Sorry if these are noobs questions, for I am a noob

bonus: How would I change players heights so their actual model is taller than their listed height? for example KD is reported to be 7' foot but listed as 6'9 This is just a bonus tho my main concern is the custom teams.
Thanks in advance