I have the perfect video tutorial to help with that, right here.
https://www.youtube.com/watch?v=wr4p2ZhMOlo&t=249s

You're going to need two softwares: Rocket Launcher and Hamachi.

Rocket Launcher is used to inject the workshop maps and replace them with the Rocket League map Underpass.

Hamachi allows you to create a server/lobby which, to easily explain it, makes Rocket League think you're in a local lobby. Which then lets you host a local lobby in Rocket League with the replaced workshop map, and all your friends in it.

Video should explain it all tho. GL!

Yeah I'm trash at explaining things so sorry if anything confuses you ecs dee

Originally posted by gogglesᵇᵈ⁽ʲ⁾:

Yeah I'm trash at explaining things so sorry if anything confuses you ecs dee

thank you so much for the help, I've ask this same question a while ago on another forum and I got no replies, so i appreciate you taking your time to reply and help me out. :)

it ain't much, but it's honest work.

Psyonix should make this kind of stuff easier. If I need to download like 20 programs to play a mod together with my friend, then that is too much for me....

Originally posted by Tinsa:

Psyonix should make this kind of stuff easier. If I need to download like 20 programs to play a mod together with my friend, then that is too much for me....

k bye

Anything that uses Hamachi. can ♥♥♥♥ right off. Prepare to waste your evening trying to get ♥♥♥♥ working, Total ♥♥♥♥

Originally posted by Zax:

Anything that uses Hamachi. can ♥♥♥♥ right off. Prepare to waste your evening trying to get ♥♥♥♥ working, Total ♥♥♥♥

what's wrong with hamachi? been using it for years and it works perfectly.

Yeah, it took like a solid 30-40 minutes for me and my friend to figure out how to use hamachi and rocket launcher to play together with mods and maps but after it was so much fun.