OCmod extension istaller - upload error

Hi,
I try to upload an extension in my OC2.0.3.1 sytem.
The FTP settings are correct, but when I click to upload file I get "403 forbidden message".
I think there is a server folder or file permission error. Which permission of folders or files should I modify? What is the needed settings?

Without knowing which operating system it's difficult to know why you are getting "403 forbidden message".

For what it's worth have a look at

http://ocextensions.co.uk/ocmod/ocmod

it may give some ideas as to alternative methods of installing OCMOD extensions