1. Install XC8/XC16/XC32 and preferably PATH enviroment to it. For example i have installed PATH
   XC8 in /opt/microchip/xc8/v2.36/bin/ directory, there is original xclm file.

2. Make on Linux/Windows this source as xclm-hack file and put it in the folder with the xclm file.

/*****************************************************************************
 *
 * xclm.c - A replacement license server for Microchip embedded compilers
 *
 *****************************************************************************/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

enum
{
    LICENSE_FREE,
    LICENSE_STANDARD,
    LICENSE_PRO,
    LICENSE_NULL,
    LICENSE_NOCPP,
    LICENSE_CPPFREE,
    LICENSE_CPPFULL
};

/* Padded keystring for XC8 compiler */
const char XC8_KEY[] = "120205690315959428539973816151144999076498629234049888"
                       "179227155534183820578631309018645587360933525814619915"
                       "779526071941849199599867328321377639683720790016145394"
                       "178294936006671919157552224249424396156390966410329115"
                       "909578096551465127991840510571525598801543710978110203"
                       "982753256678760352233698494166181105701471577863949973"
                       "752378527793703095602570185318279000307654710756304884"
                       "332086971157374238079344503160762531771453544441183117"
                       "818224971852635709182448998796203508335756172022603393"
                       "785870328131267807990054177348691152537065623705744096"
                       "622171290262732073236149224291304052855537234103307757"
                       "779806424202430488281521000914602653822069627155202082"
                       "274335001015294801198690117625951676366998171835575234"
                       "880703719555742347294083595208861666202572853755813079"
                       "282586487282173705566196898952662018776810629200817792"
                       "338135876828426412432431480282173674506720693507626895"
                       "304345939375032966363775750624733239923482883107733905"
                       "27680200757984356120205690";

int main(int argc, char *argv[])
{
    int license = LICENSE_FREE;
    int ii;

    for (ii = 0; ii < argc; ++ii)
    {
        if (!strcmp(argv[ii], "swxc32") ||
            !strcmp(argv[ii], "swxc16") ||
            !strcmp(argv[ii], "swxc8"))
        {
            license = LICENSE_PRO;
        }
        else if (!strcmp(argv[ii], "swxcpp32"))
        {
            license = LICENSE_CPPFULL;
        }
        else if (!strcmp(argv[ii], "-hash"))
        {
            int index = atoi(argv[ii+1]);
            printf("%.10s", &XC8_KEY[index]);
        }
    }
    return license;
}
/*****************************************************************************/

3. Linux(command prompt):
   sudo apt-get update
   sudo apt-get install binfmt-support
   sudo update-binfmts --install xclm-hack /opt/microchip/xc8/v2.36/bin/xclm-hack --magic `(hexdump -e '16/1 "%02x"' -n 64 /opt/microchip/xc8/v2.36/bin/xclm | sed -e 's/../\\\x&/g')`
   sudo service binfmt-support start

   Now the "magic" for xclm-hack should display this format of the original xclm:
   dmytro@DESKTOP-3P3B9MQ:~$ sudo update-binfmts --display
   python3.8 (disabled):
        package = python3.8
           type = magic
         offset = 0
          magic = \x55\x0d\x0d\x0a
           mask =
    interpreter = /usr/bin/python3.8
       detector =
   xclm-hack (enabled):
        package = <local>
           type = magic
         offset = 0
          magic = \x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x3e\x00\x01\x00\x00\x00\x88\x41\x40\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\xa0\x05\x26\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00\x38\x00\x09\x00\x40\x00\x1d\x00\x1c\x00
           mask =
    interpreter = /opt/microchip/xc8/v2.36/bin/xclm-hack
       detector =
   dmytro@DESKTOP-3P3B9MQ:~$

   And when we type "xclm" there should be no output.
   Voila, the Pro version should work now.
   Was Tested on Real Ubuntu 20.04/WSL Ubuntu 20.04
   
3. Windows(command prompt):
   
   C:\WINDOWS\system32>reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\xclm.exe" /t REG_SZ /v "debugger" /d "xclm-hack.exe"
   The operation completed successfully.
   
   C:\WINDOWS\system32>
   
   And when we type "xclm" there should be no output.
   Voila, the Pro version should work now.
   Was Tested on Win10/Win11