How can i remove a file??

Use the rm command from the command line. Enter man rm or info rm for details.

Note that the command man -k search_for or info --apropos search_for will usually list all entries for commands (and subroutines) with "search_for" (where, of course, "search_for" is what you're interested in finding) in their keyword list.

If you're using the KDE windowing system, start the Konqueror command, set the "view" option to "File Management," highlight the file and type <shift>-<delete> to delete the file, or right-click on it and then on the option to send it to the "trash" can. If you're using GNOME, there is a similar option in Nautilus.

If your problem is that these commands don't work for the file, perhaps you don't have permission to delete it. In order to delete a file, you most either own the file or have write permission to it. Look at the chmod or chown commands for information about changing ownership, or the "permissions" of the file in either konqueror or nautilus.

Edit: I just noticed that your question was in the "Programming" forum. If you're asking about removing a file from within a program, it, of course, depends on the specific programming language you're using. So, if this is the case, tell us which language you're using (or read the language manual) for specific help.