It is no longer possible to transfer characters in GTA V.
A Rockstar article also states:
NoteQuestion: Character transfers for GTA Online will be discontinued as of March 6Can I transfer my character from my current platform to another?
Answer: No, 2017. Please see this article for more information: https://support.rockstargames.com/hc/en-us/articles/115002343808is not possible. There is currently no feature available to transfer character data between platforms.
There are no legal ways to transfer a character in GTA V anymore. Since the data for characters is online based, you'd be hard pressed trying to transfer a character by different means, if it's even possible. Support also states that if you attempt to transfer a character, nothing will happen.