1. Open Filezilla and connect to your account.
2. Navigate to and select the files/folders you wish to alter permissions for, Right click, File Permissions….
3. Set the permissions you wish to apply. Recursion can also be selected to apply the permission set to all child directories/files.
The recommended permissions to set are as follows:
Folders/Directories: 755 (-rwxr-xr-x)
Single Files: 644 (-rw-r–r–)
Some Sensitive Files such as wp-config.php: 440 or 400 (-r–r—– or -r——–)
Please note: It is never recommended to have 777 (-rwxrwxrwx) permissions set on any file or directory.