@bguerville basically explained it pretty well. There is also a text document on github with steps to take when just the revision is updated.
https://github.com/PS3Xploit/PS3HEN/blob/master/docs/update_hen_src_version_only.txt
Pretty much just modify the bin. Its only 4 bytes long, for example 03 22 is the bytes currently. Then as bguerville said, you have to change the path to hen_version.bin in the sprx. There are 2 paths it looks for, one for release and one for development, [server]/hen/hen_version.bin and [server]/hen/hen_version_dev.bin
Edit: the server host also needs updated , as per your requirements.
#define HOST_SERVER "
www.ps3xploit.me"
And lastly, for the package paths, you need to change this line
const wchar_t* pkg_url_tmp = L"
http://www.ps3xploit.me/hen/%ls/%ls/%ls/installer/Latest_HEN_Installer%ls";