[gurmani11]

pawn Код:

CMD:setname (playerid, params[])

{
    new id, name[25],str[120];
    if(sscanf(params, "us[25]", id))return SendClientMessage(playerid, COLOR_RED, "Error: Usage: /Setname [id]");

    if(strlen(name) < 3)return SendClientMessage(playerid, COLOR_RED, "Error: The length of name is lower than 3!");
    if(strlen(name) > MAX_PLAYER_NAME)return SendClientMessage(playerid, COLOR_RED, "Error: The length of name exceeds the limit!");
    new file[64];
    format(file, sizeof(file), "/Users/%s.ini", name);// change it to your User Path
    if (fexist(file)) return SendClientMessage(playerid, COLOR_RED, "Error: That name is already in use!");
    fremove(UserPath(id));// UserPath is a stock in my code you can change it to your's
    SetPlayerName(id,name);
        //and save the stats of player like you do in OnPlayerDisconnect
//Example: 
        SaveStats(id);
    return 1;
}

Hope you will not understand it... because you beg for codes.. instead of googling or learning it..