There is a post for it from @Expiker21:
https://www.mpgh.net/forum/showthread.php?t=1485197
If I'm not allowed to post links, the name of the post is "Changing player level and rank DBD 3.4.2".
Even it was for 3.4.2, it worked for me in version 3.6.2. I don't know if it works on 3.7.0.
But anyways, its always risky (Hacking shards is direct revenue loss for BHVR therefore they will do their best to ban all people who do this.) like @Expiker21 said.