BK if your friend has a laptop or pc there's a chance that he can download one directory at a time to one of those devices and then upload them to Geocities by using the Choose File option BUT this options will probably be limited because I assume that with geocities being free, that he's only allowed to upload so many megabytes at a time and I also assume geocities has a cap on how many mb of space they allow each user to have so his webserver may have more megabytes of stuff then geocities will allow.

There's also a possibility that on whatever device he's using, he can open geocities in one tab and his web server in the other tab and use "copy" to copy and paste from the web server to geocities.