Cardboard plug stuck to mold !

hello everyone,
hope you all are doing well, i am new to this website
i was working on a plug and mold for a monocoque of a race car, i build the plug from carboard and paperboards and gave it thickness so it was hard enough then i added primer to it and them started making the mold by cutting it in half longitudinally, the problem is when i came to release, the plug was ripped in half, i should have cover it with some epoxy and cloth fiberglass to protect but anyway managed to fix it for the upper part and now covered it with epoxy and cloth fiberglass. Now for the lower mold parts of the carboard got stuck to it so i removed many of it with a hammer and a wood carving tool but still many stuck to the surface so any idea on how can i removed the red please ? (the links below show 3 pictures of how the mold is now with paperboard stuck to it )
http://i96.photobucket.com/albums/l196/mac_987/P1070789_zps0reqq1id.jpg
http://i96.photobucket.com/albums/l196/mac_987/P1070791_zpsw2fdxwmy.jpg
http://i96.photobucket.com/albums/l196/mac_987/P1070790_zpsj2ksyl1u.jpg

yikes! No really good way other than sanding. Might be able to sandblast it(?). Probably best is to get it as good as you can, PVA it, Splash a plug, fix the plug nicely, splash a new mould.

I concur. I wouldn’t spend the time trying to salvage that one.

ok thank you guys for the reply,
i sand it as much as possible and used a carving tool to take the stuck off

about the mold unfortunately the lower part is broken into pieces i managed to fixed the upper and added epoxy and cloth fiber to it to prevent it from breaking like the lower