cannot access/restore backup files

My wife runs Ubuntu 16.04 32 bit. After problems with libre office I decided to update Ubuntu to 18,04 64bit. I backed up all files with dejadup and installed Ubuntu 18.04 64 bit alongside the old Ubuntu 16.04 32bit. The new 18.04 64 bit installation is fine however when I came to restore the backup files from the 32 bit os to the new 64 bit os installation I got the message "you don't have permission to access the Files".
How do I change the permissions to enable me to access the Ubuntu 32bit backup and restore the files to the new Ubuntu18.04 64 bit system.

I am still in need of help on this problem