How to change directory permissions

[argie]

I want to replace some of the graphics used by HTC Home. When I try to store my new files in the /Windows directory with the same name as the existing files, the system tells me I don't have permissions to write over a read-only file.

I cannot disable the read-only flag, and I read this forum and all others in XDA-developers before giving up.

Can anyone tell me how to change permissions?

Thanks,

George