Help a new guy with TL enclosure

[thematrimix]

Hello,
how did you invert the box shape on the second page of the Sheet as you have shown In the second figure.

Boy this is now an old thread. The simple answer to your questions ...

1) Unprotect the sheet
2) Copy the image
3) Paste it into your favorite editor (Windows I use Paint.Net, Linux GIMP, Mac dont know)
4) Invert the image edit the text to make it look right
5) Paste the image back to the sheet and re0protect the sheet