Pancar: It is bad form to hijack a thread started by someone else on a totally different subject.  Next time start a new thread.

You can find numerous PDF to DWG conversion programs using a simple Internet search.  Many offer a trial version.  Test a couple and then make your choice.  Be aware that many conversion programs do a relatively poor job and will cause you headaches when it comes time to edit the converted drawing.

Try this
Purge alternative command usinh lisp
Copy this code into the ***.lsp file
and load it appload
and use "purgee" command
Have a nice work

Osman YILMAZ

(vl-load-com)
(defun c:purgee ()
(command "qsave")
(command "clayer" "0" "purge" "a" "*" "n")
(command "qsave")
(vlax-for n (vla-get-blocks                 (vla-get-activedocument (vlax-get-acad-object))) (vl-catch-all-apply 'vla-delete (list n)))
(command "qsave")
(vlax-for n (vla-get-layers                 (vla-get-activedocument (vlax-get-acad-object))) (vl-catch-all-apply 'vla-delete (list n)))
(command "qsave")
(vlax-for n (vla-get-linetypes              (vla-get-activedocument (vlax-get-acad-object))) (vl-catch-all-apply 'vla-delete (list n)))
(command "qsave")
(vlax-for n (vla-get-textstyles             (vla-get-activedocument (vlax-get-acad-object))) (vl-catch-all-apply 'vla-delete (list n)))
(command "qsave")
(vlax-for n (vla-get-registeredapplications (vla-get-activedocument (vlax-get-acad-object))) (vl-catch-all-apply 'vla-delete (list n)))
(command "qsave")
(command "audit" "Y" )
(command "qsave")
(command "clayer" "0" "purge" "a" "*" "n")
(command "qsave")
(princ)
)

Please help with this, I received a file so heavy, all the layers was deleted but anyway the file continue so heavy , could somebody  tell me what can i do, I will apreciatte all your help.