I'm use to DM/GMing but this is my first time doing so in the Shadowrun universe, normally I use d20 Modern or DnD 4th. However, most of my group is out of town and the rest of the group (3 total) don't want to wait for them to get back before doing some roleplaying. I remembered that I have a few copies of Shadowrun 4th Core Rules in my personal library, got it around when it first came out and bought four copies, one for me and the others if anyone needed to borrow one. Well, we decided to go with Shadowrun until the others get back in a month. Anyway, the group wanted to use my d20 setting in the Shadowrun universe and I'm trying to decide on how to make it fit.
The setting is called Free Saints City and is located off the coast of California. It's a large city on a man made island that was built by a corporation I call HeavenTech. The corporation built it to house it's employees and it's like a normal city, more or less. However, Heaven Tech wound up falling apart, but most of their employees stayed in Free Saints City. With HeavenTech gone, and therefore also the money that funded the police force, various gangs took over the city. The Blood Pack, Da' High Rollerz, El Guerreros, Grey's Graveyarders, House Carstein and Plum St. Outlawz are the major gangs in the city and are divided into two factions, the Supernatural Syndicate, made up of the Blood Pack, House Carstein and Graveyarders, and the Big Time Playas, made up of the Outlawz, Rollerz and Guerreros. A corporation called the Raven Corporation bought the rights to the island and have moved in as well and fight the gangs of the city. Another group emerged called the White Knights, they're a group of vigilantes and ex-FSPD officers funded by the US Military to retake Free Saints City and claim it for the US Government, making the White Knights not only enemies to the Gangs but also the Raven Corporation.
That's just the basic information. I'm having problems adapting it to the Shadowrun universe and could use some help.