There is a simple way.
Dropbox with a archive with a password.
Someone needs the dropbox link to start with so it is safe to start with, once you know the person has it you can remove the link or even set a duration to the file.
If you use 7zip to archive the file, add a password using the AES-256 encryption.
I dont think windows zip supports AES-256 encrypted password protected zip files.
But use a large password made up with lower case, uppercase, numbers and symbols.
eg.
R0b1n_G7-p@4^3+
The other method requires downloading the ZIP, then unzipping it, entering the password, then finding the unzipped files etc. Trust me, you wouldn't believe how difficult some people find this
7zip is a free, small program that should be on all computers as it does compression better than the windows zip utility.
When you want to unzip a password protected archive, you just go to unzip it prompts you to enter password and when correct it unzips where you told it to unzip
You could do the following.
Folder.zip
|_READTHIS.TXT(instructions on how to unzip)
|_archive.7z
I know it seems basic to us but the people at the other end barely know how to turn on a computer! I guess that's why all cloud providers charge for password protected links.
Thanks for the offer DQuaN but it's sensitive info so I can't let it leave my control hosting it.