The Linux delete command is "rm" (short for remove).
Just use "rm <filename>" then hit the return key. If there are many files you can use wildcards, for example "rm *.tmp" will remove all files ending ".tmp".
If the file is protected or not owned by you, you might have to use "sudo" ahead of the command, for example "sudo rm <filename>". It will ask for the password before granting you permission to delete another users files.
I'm not sure if it works in Centos but you can try opening a terminal window and a window showing the temporary files. Type "rm " (note the space) then drag the file from the list to the terminal window. If it works as it does in my Linux, the path and file name will be copied across automatically.
Brian.