Not hard are all.
I use https://github.com/benthecarman/lnurl-server
Yes. Prerequisites: domain name, public webserver. You can do it, don't be afraid to constantly ask questions.
Discussion
It's weird that I zapped myself but I sometimes do it to make sure it's still working 🤣
How hard or not would this be to run on a different machine from my lightning node?
Entirely possible (I have a similar setup). Ideally you need a wireguard tunnel between that different machine and your lightning node.
1. Setup the wireguard tunnel
2. Configure lnd to bind its grpc interface to the node"s wireguard IP
3. Make sure lnd grpc port 1009 is open in the firewall so that the oher machine can access it through the wireguard tunnel
4. Copy the cert and macaroon files to that other machine
5. Adjust the lnurl-server flags accordingly, namely --lnd-host
You can look at my wireguard guide for help with step 1:
nostr:naddr1qq8kwatfv3jj6amfwfjkwatpwfjqygxsm6lelvfda7qlg0tud9pfhduysy4vrexj65azqtdk4tr75j6xdspsgqqqw4rsg32ag8
For the other steps, you need to get a bit comfortable with linux and networking.