Required Software

AP Setup

Run Setup.MultiworldGG.version number.exe but don't open the launcher yet
Double click simpsonshitandrun.apworld, it should pop up something saying APWorld successfully installed (and telling you to restart the AP launcher if you have it open) (this is not needed if you run MultiworldGG)

Open MultiworldGGLauncher.exe in the MultiworldGG folder created when you ran the AP setup
Search for and click Generate Template Yamls which will open a folder full of yamls
Find The Simpsons Hit and Run.yaml and edit it to your liking.
Save your edited .yaml in MultiworldGG/Players which is 1 folder up from the template yaml folder that opened.
Optionally add more yamls for other players or other games you want to play. The multiworld will have 1 slot per yaml included here.
In the AP Launcher again, search for and click Generate

Go to MultiworldGG and click Get Started (top right) -> Host Game then click Upload File
Go to the Archipelago/output folder and choose the .zip that was created when you clicked Generate (should be the newest one)
Click Create Room and wait for it to spin up. This is the room. You're good to go once there's a line that says /connect multiworld.gg:{port}

Note: You can also self host an MultiworldGG game server, but that's outside the scope of this guide.

Follow these instructions to setup Lucas' Mod Manager.
Place SHARAP.lmlm in the mods folder.
Enable Archipelago Randomizer by clicking the checkbox in the Mods List. Currently, no other major mods are supported.
Check here for more help installing mods.
Under the "Settings" tab of the mod launcher, there are several optional mods. Don't enable anything that changes gameplay, but graphical changes or setting changes are fine.
Install .NET 8 from the link above. Make sure to install the x86 version. The site will default to x64 as that's more modern, but SHAR needs x86.
Finally, extract SHARRandomizer.zip where ever you'd like.

Download the Config file by going to the MultiworldGG Room and clicking "Download Patch File"
Extract the "SHAR.ini" file from the downloaded .zip and place it in "Documents\My Games\Lucas' Simpsons Hit & Run Mod Launcher\Saved Games\APSHARRandomizer" If that folder doesn't exist, create it. You can also reach the folder by clicking Open in the mod launcher and choosing Saved Games if the mod is enabled.
Run SHARRandomizer.exe
First it'll ask for the connection string. If you're hosting on the AP website as described earlier, then you can just enter the port
Then it'll ask for the slot name, this is what you put as Name in the yaml and also shows in the room on the website
Then it'll ask for a password. By default this is blank.
Launch the game via Lucas' Mod Launcher ensuring the above steps have been completed.
Enjoy!

This is in active development! Check the pinned FAQ and/or ask for help in the Discord channel.