How to access files in "Trash" folders/files, in Ubuntu

I recently emptied my trash folder in Kubuntu 17.10, however I couldn't removed one folder.
after some digging in, it turned out it's permission issue.
anyway, I came across, a same post in ask Ubuntu,
website. It uses TrashCli to do this in terminal.
here is the steps: (you can check the original post HERE)

• Install trash-cli: $sudo apt-get install trash-cli

• Put files in the trash with: $trash file1 file2

• List files in trash: $trash-list

• Empty trash with: $trash-empty