A very common way ->
1) Install ssh-server/telnet-server on the remote linux host.
2) Install ssh-client/telnet-client on your machine. If you have windows install PuTTY.
3) Connect to the remote linux host via ssh/telnet. Use chmod command to change file permissions.
chmod 755 <filename>
chmod -cR 755 <directoryname>
For more information on chmod, tpye man chmod on the command prompt.