For example I want to convert the G-League and China teams from the Prelude in current teams.
I hope someone can help me with this. Thanks!
Actually I get this:

I copy here some explanations from Carolus´s post in NBA 2K18.
"00 - regular team
04 - classic team
08 - euroleague team
58 - expansion team
60 - all-time team"
"- Using a hex editor (the simpler, the better.. I use one called HxD), write the name of the team you want to find. For instance, "Dallas", "Mavericks", "Wizards", whatever.
- There'll be an array of bytes that represent the name you just wrote. For "Dallas", this value will be "44 61 6C 6C 61 73". However, if you search for this exact value, probably you won't find anything. So...
- Insert "00" between every byte. So "44 61 6C 6C 61 73" becomes "44 00 61 00 6C 00 6C 00 61 00 73" (which becomes "D.a.l.l.a.s"), for instance. You can now search for this value using CE. In "value type", select "array of bytes". You will find like 100 instances. So..
- Add some "00" before the "44" (example). This way you search only for instances where there are a bunch of zeroes prior to the team name, which is usually the case in regions like the one you want to edit.
- Even if you do this, you still are going to find something like 15 instances, all of them similar to the one from that screenshot. Some of them are all-time teams (you'll see the names), retro teams ("Dallas" has two, for example), and unfortunately some duplicates of the regular teams. Some instances don't change anything upon editing. There's only one that is responsible for the team you want to edit. Usually it is one of the last ones displayed on the list.
- Browse the memory region of the chosen instance. Copy all the bytes from the first name of the team until the first name of the next team. Paste on your hex editor. Then look for the bytes localized in the same place as the highlighted byte on that screenshot. If the team is regular, 00 will be there. If it's a classic team, 04. All-time team, 60. If you use HxD, the byte you want to change will be exactly at the last position of the row 6E0.
- As soon as you learned exactly where the byte is, return to the memory browse and change the byte. You just changed the team type. Save your roster in game and there you go.
Sorry for english mistakes.."