Extract file nex2000eng.ZIP on your hard drive
ex; C:/ (the directory nex2000eng will be created automatically)
In AutoCAD, click the command ‘appload’, load file, select the file
C:/nex2000eng/insnexaeng.vlx and click OK A dialogue box
'Select installation nexacor add on' will open 
Select the file 'Get_env_nex.VLX' in the directory
C:/nex2000eng/Install-Nexacor and click OPEN